We've all heard financial experts talk about "shorting" the market, and the role that "short-selling" arguably played in the global financial collapse. But is it really such an awful financial tool? And are U.S. regulators correct in cracking down on the industry?

And in a Web exclusive, Stephen Figlewski of New York University take a long look at the world of short-selling.

Hong Kong, China - As long as there are free markets and humans remain emotional creatures, there will always be financial crises.

So says renowned British historian Niall Ferguson. The Harvard University professor and I had a chance to meet in Hong Kong at a recent investors' conference. He shared his observations on the current economic crisis.

CNN: Is there anything unique about this recession?

Ferguson: This isn't a recession is the first point to make. It's a near depression. In fact, I am calling it the Slight Depression to distinguish it from the Great Depression of 1929 to 1933. And the unique thing is that we nearly repeated history. In other words we nearly repeated the Great Depression, but we avoided it with massive monetary and fiscal stimulus. So we are in new territory.

CNN: When does government intervention work?

Ferguson: We need to be very careful when we talk about government intervention. That covers a multitude of sins. There was a lot of government intervention in the Soviet Union and we know how that story ended. So we are talking very specifically here about two policies: one is the use of central bank money creating power to avoid a liquidity crisis that crunches the entire banking system. So intervention by the (U.S.) Federal Reserve beginning in 2007 and escalating in September of 2008 was primarily designed to avoid massive bank failures of the sort that made the Depression so serious in the early 1930s. And I think there is no question that we have learned from history and Ben Bernanke, as chairman of the Fed, has learned from history, that it's a good idea to avoid a generalized collapse of the banking system.

CNN: When does government intervention not work?

Ferguson: The other kind of government intervention, which is slightly more problematic, is the sort in which the government runs a large deficit in order to stimulate the economy by building roads and building bridges in order to get people back to work in the hope that in doing that, it will generate a recovery. This is the model developed by John Maynard Keynes back in the 1930s and it's been used by countries around the world to varying degrees. And to some extent, this has been effective. But the problem is, in the United States, you are adding a stimulus on top of an already huge structural deficit in the public finances, and the prospect of a trillion dollars of new borrowing every year for the decade ahead, that scares me and it should scare everybody.

CNN: There's been a backlash against the financial world, especially Wall Street. Have we seen the same level of fury after past crises and where does that vitriol lead?

Ferguson: It's not, by any means, the first time that people have felt furious of what they have seen going on in Wall Street: a financial speculative bubble that bursts and causes a recession which drives other people, ordinary folks out of jobs. The question is just how far this populous backlash is going to go in the United States and indeed around the world now. My suspicion is that it's got a ways to go. Each time an American loses his or her job, not surprisingly, he or she looks around and asks who's to blame for this. And when they see on Wall Street, the banks paying out million-dollar bonuses with what appears to be, and in some cases is, taxpayer money from the TARP fund, I am not at all surprised that people feel mad. And when they feel mad, they turn around and they say, 'How can I express this anger? Who can I vote for who is going to articulate my feelings of frustration?' And I wouldn't be at all surprised to see, as we approach the mid-term elections, more and more politicians, particularly Republicans, trying to articulate that sense of popular grievance.

What lessons have you learned from the current economic crisis? Tell us what your experiences are.

LONDON, England – Based on fundamentals, the markets shouldn't be at the levels they've reached. Some hard cold realities have been reminding investors that the long awaited recovery may turn out to be more anemic than anticipated.

Have markets over-heated?

Take last week for instance. U.S. stocks fell worst than expected on monthly manufacturing numbers and a horrific employment report.

The number of U.S. workers on payrolls fell by 263,000 in September - much worse than expected - and the unemployment rate rose to 9.8 percent, a 26-year high. To make matters worse, the average workweek fell to a record low of 33 hours, hardly encouraging to those who have been buying stocks on recovery hopes.

Nouriel Roubini, who predicted the financial crisis, is bearish on the market. "Markets have gone up too much, too soon,too fast," he said in an interview over the weekend with Bloomberg.

"I see the risk of a correction, especially when the markets now realize that the recovery is not rapid and V-shaped, but more like U-shaped, that might be in the fourth quarter or the first quarter of next year," he said.

Roubini is not alone in his thinking. The head of global bank HSBC, Michal Geoghegan, is worried the economic recession could be worst than some anticipate.

"Is this a V recovery or a W?" Mr Geoghegan asked in an interview with the Financial Times. "[I think] it’s the latter. [If I’m right] we have to be very careful we don’t grow the balance sheet so far before the recovery has come only to write it back into the impairment line later on. I’m cautious about growing too fast."

And economist Lena Komileva of Tullet Prebon said the weak data, specifically referring to the manufacturing data out of the U.S. last week, "do challenge the market's optimism that this year's capital markets rally is the bellweather of a V-shaped economic recovery and it forces a negative revision of future quarters growth projections, which challenges current valuations."

In simple talk, the markets are ahead of themselves. The global equity rally has added about $20 trillion to the value of stocks worldwide since this year's low on March 9, according to Bloomberg.

Governments have spent about $2 trillion on stimulus, while central banks have taken extraordinary measures to try and get growth moving again.

All that liquidity and hopes of a global recovery have pushed stocks substantially higher, more than 50 percent for the S&P 500, and nearly 50 percent for Europe's Dow Jones Stoxx 600 index from their March lows.

While markets are off their best levels, they are still too high based on economic reality. I suspect the disappointing economic numbers last week, won't be the last. If Roubini and some others are right, markets have much further to fall.

Do you think the markets are too high?

LONDON, England – On a quiet summer day in August, when many in London's financial district are away, or wishing they were away, comes a lightning bolt from the head of the Financial Services Authority.

Adair Turner proposes the idea of a special tax on financial transactions.

Adair Turner, the man in charge of regulating the City of London, has said that some parts of the financial sector have grown "beyond a socially reasonable size," and some of what it does as "socially useless activity."

In short he thinks financial services account for too much of Britain's output, robbing other sectors of some of the best and brightest.

To underscore his point, he looks at what “percentage of highly intelligent people from our best universities went into financial services." And then goes to say, "Unless you've got a theory that explains why financial intermediation suddenly needs all this extra resource, there is something of a conundrum. Is it really the case that financial intermediation today is a more complex thing that a decade or two back?”

He proposes the idea of a special tax on financial transactions.

His is not a new idea.

Originally, an economist named James Tobin suggested a special tax on foreign currency transactions to curb speculation. Then in 2005, then president of France, Jacques Chirac, placed a "Tobin tax" on financial transactions to deal with what he perceived to be the excesses of "liberal globalization."

"If you want to stop excessive pay in a swollen financial sector you have to reduce the size of that sector or apply special taxes to its pre-remuneration profit," Turner said.

It's clear that freewheeling capitalism didn't work, that policymakers need to devise ways to curb excessive risk taking. Higher capital requirements should be the first line of defense.

Unsurprisingly, Turner's possible solution and open questioning of whether the financial district is too large, is already provoking sharp debate and response. He even went so far as too suggest that London's competitive advantage as one of the world's premier financial hubs shouldn't be defended at any cost.

The head of the British Bankers Association Angela Knight, did not mince words in response. "I think that if we say we do not want to have an international, competitive industry here, then we will do to financial services what we have done to manufacturing and engineering in the past and that is have it as a minor industry and lose it to others," she said.

I agree with Knight.

Yes, there have been excesses and recklessness in the financial sector that will take decades to unwind, including eye-popping amounts of money bailing out a financial system that could have been put to much more productive use.

But haven't they acknowledged the excesses? Let's not further undermine an economy already on its knees by making it less competitive and attractive. Let's first start with better supervision.

Do you agree there should be global taxes on financial transactions as a way of curbing excesses? Would such taxes be effective?

HONG KONG, China - Confused by the rules and regulations of China's stock markets? You are not alone.

Probably one of the most common questions I am asked as Asia Business Editor is how to invest in China, especially its stock markets. The markets are up more than 80 percent this year. With the world economy in turmoil, many investors see China as a bright spot on an otherwise dark landscape. They want in.

Market watchers debate if China's stock markets are headed into bubble territory and warn that trading is still a new phenomenon in the country. Information is scarce, spotty, and often only in Chinese. Market swings are extremely volatile.

But with that warning in mind, here is a little guide to help the intrepid better understand China's stock investing ABC's.

A-shares: Stocks of Chinese companies listed in mainland China - in Shenzhen and Shanghai. These shares are sold in Chinese yuan, largely to local investors. Foreign individual investors cannot buy A-shares directly. International institutions can, but with limits. "China has a very restrictive policy in terms of allowing foreign investing into the local stock market," explains Peter Alexander of Shanghai-based Z-Ben Advisors. "They don't actually need foreign investors because there is enormous amount of demand locally." Alexander suggests going through a bank or a mutual fund.

B-shares: B-shares are also stocks of Chinese companies listed in Shenzhen and Shanghai. These stocks were originally meant for foreign investors and are sold in U.S. and Hong Kong dollars. The B-share market never really took off in the way the Chinese government intended. Chinese companies looking for foreign funds often choose instead to list on the Hong Kong stock market. The government has recently loosened the rules to allow more domestic investors to buy B-shares though the number of companies is pretty small.

H-shares: If anyone wants to trade in Chinese stocks directly, Alexander says Hong Kong is the place to do it. "Over the past decade, a number of Chinese companies have begun to list on the Hong Kong market," he told me. "Banks, petroleum companies, every type of industry, big companies, very liquid." These shares trade in Hong Kong dollars and are governed by international standards, so buying and selling H-shares is more transparent. Information on these listed companies, Alexander says, is easier to find.

ADRs: American Depositary Receipts. These are shares of non-U.S. – in this case Chinese - companies listed in New York. Investors can buy big Chinese names such as China Mobile or PetroChina but the selection is limited.

Investing in Chinese companies is a bit of a letters game - and, certainly, a risky one.

LONDON, England – Last week when I appeared on CNN to talk about earnings, I raised the issue of the quality of the U.S earnings.

Wall Street gains sent the Dow above 9,000 points for the first time since January.

Investors have been pushing stocks higher fueled by better than expected earnings. The Dow broke through 9,000 for first time since January, while the S&P 500 has shot up 11 percent in the past two weeks. The U.S. earnings season has fueled a global rally.

But are investors getting too euphoric? If you look at the revenue side of the earnings, not all is well. Take the 143 companies in the S&P 500 who reported last week. Revenues actual fell on average 10 percent from the same period a year ago, according to Bloomberg data.

Steven Ricchiuto, chief economist at Mizuo Securities USA hit the nail on the head when he spoke about the divergence between earnings and revenues.

"We know companies are cutting costs at a record pace, and that is helping earnings. But you can't keep on shrinking your way to profitability. Eventually, you do damage to your end users. You have to get revenues up to have a sustainable upturn."

David Rosenberg, chief economist and strategist at Gluskin Sheff, echoed similar sentiments when quoted by the Financial Times.

"Earnings may be beating low-balled estimates for the majority of S&P 500 companies, but there is no questioning the fact that we are also seeing a sustained decline in revenues."

"What we are still witnessing is a trading opportunity rather than a fundamental shift in the outlook. We must take into account what the risks are going to be once the buying momentum is lost," he added.

The bottom line is that companies can't indefinitely cut costs, they need to get revenues moving higher. But every time they shed a job, that means one less consumer spending as much money in the economy, undermining the prospects for recovery, which in turn of course, hurts companies earnings prospects.

In a research note this month, the economist Nouriel Roubini sounded a note of caution.

"Expectations of corporate earnings will have to be downgraded again. Demand will be weak, most prices will be falling, and companies will therefore have little pricing power and their profit margins will remain squeezed. The expectation that in these conditions profits will rebound strongly is quite far-fetched."

Roubini is worth listening to, because he's the guy who predicted the credit mess. As I've written many times before, any sustainable recovery is still far away.

But for now, investors aren't too concerned why companies are beating earnings expectations; that they are is enough. A closer analysis might make investors a little less euphoric.

Do you agree or disagree?

(CNN) – The Quest Means Business team has been tasked to try and explain business jargon to its viewers.

We are often guilty of throwing terms around when talking about company results that are difficult to explain in a sentence or two.

EBITDA (Earnings Before Interest, Taxes, Depreciation and Amortization) is one of those for me.

So I was pleased to delve into it, not only to try and explain it, but also to really get my head around it. Why did companies publish EBITDA figures during the dotcom bubble era? Why do few companies use it now? Why is it not acceptable under so-called U.S. Generally Accepted Accounting Principles (GAAP)?

Ok, I will try and explain it again. Basically (and really basically) it’s a way to express a company’s earnings (the same as net income or profits or the “bottom line”) in a given period. But it is a number that is expressed before the company strips out recurring charges or costs like taxes, interest paid on debt, the loss of value of assets etc. (If I write anymore, I will confuse myself).

Companies use EBITDA (and ITDA and other complication formulae) especially when the number is positive while all others may be negative: “Company X lost six billion dollars last quarter, but EBITDA grew 15 percent!”

To be fair it is a way to try and show a consistent number if a new company is growing fast and spending huge amounts of money so it has no hopes of turning a profit. That is why it became a popular number during the late 1990s.

Today, private equity likes to look at EBITDA figures during a potential takeover because it helps to clarify a company’s underlying ability to earn money.

Is it any clearer to you now?

If not, the video below shows me trying to explain it to a classroom full of children. They were enthusiastic to learn and were shouting “EBITDA” when we packed up to leave their London school.

LONDON, England– In the past week, investor sentiment has turned decidedly more positive. On Monday, the Standard and Poor's 500 Index hit an eight-month high. Better than expected earnings from Goldman Sachs in financials, to Intel in tech, to Caterpillar the biggest maker of earth moving equipment, have all helped push the market higher.

Investment banks are raising their year-end projections for the S&P 500. Credit Suisse is advising clients to cut their bond holdings and buy stocks, reversing their advice from June. The bank has raised its year-end guidance for the benchmark index by 14 percent to 1,050, citing better earnings and economic conditions.

Goldman Sachs is also turning more bullish. It has a year-end target of 1,060 for the S&P 500. "Improvement in ex-financial earnings per share, stabilization in profit margins and higher forward EPS guidance all point to a rising market through 2009," its chief U.S. investment strategist, David Kostin wrote this week.

He also raised his 2009 and 2010 earnings estimates for the S&P 500 companies to $52 a share and $75 a share, substantially higher than his previous estimates (a 30 percent increase over his previous 2009 estimate and a 19 percent increase over his previous 2010 estimate.)

However, Kostin is hedging his bets, saying the biggest risk to his forecast is the possibility of a prolonged economic slump.

He also points to budget cutbacks from state and local governments, a higher savings rate, and a weak housing market as keeping consumer and business spending in check.

Goldman is among the most bullish of Wall Street investment banks on equities. Others include JP Morgan which has a target of 1100 year end for the S&P 500. At the other end of the spectrum, HSBC and Morgan Stanley both have a target of 900.

The S&P 500 has risen some 40 percent from its March low, and if the bulls are right, the rally has further to go. So far, some 79 percent of S&P 500 companies have beaten earnings forecasts, the best showing since 1993.

For the rally to continue, companies will have to continue to beat forecasts, and investors will have to remain confident that the economy will continue to improve.

Do you think the rally has come too far too fast?

LONDON, England - The stock market rally off the March lows, has been nothing short of spectacular.

The FTSE All World Index has shot up more than 60 percent. At several conferences I've attended, the majority of those I've asked, seem skeptical that the rally can be sustained, and for many they wouldn't be surprised if the market retests its lows.

Some don't believe it will, that the forced selling by hedge funds and others is past. But a Barclays Capital survey shows that six out of 10 respondents think the current rally is a "bear market rally." The survey includes asset managers, international corporate customers, hedge funds, and central banks.

Furthermore, fewer than five percent of those surveyed believe there will be a "V-shaped" recovery over the next year. That is, a sharp downturn followed by a sharp rebound in economic activity.

The majority - nearly 70 percent - think either you get a "W-shaped" recovery, that is a temporary rebound followed by weakness, or a "U-shaped" recovery, which means growth remains anemic for sometime before you get a gradual recovery.

As I mentioned in my last blog, many of those I speak with believe a sustained recovery is at least 18 months or further away. The Barclay's Capital survey would seem to reinforce this view.

Any sharp set back in the market would of course be damaging to consumer confidence, further undermining the timing of any economic recovery.

The bulls will argue that markets always anticipate recovery. But what the professionals in the Barclay's survey, and my own informal polling suggest, is that this rally may be ahead of itself.

 What do you think - is this rally a bear market trap?

A lot has been made about the so called green shoots of recovery. And I'll be the first to admit it's a lot better than being in freefall.

But let's not get too excited here. There's a huge space between being out of freefall and getting to a sustained recovery.

When I think about recovery, I'm not talking about the end of negative growth. To me real recovery is one which growth rates are closer to longer term trends.

Don't get me wrong, the huge improvements we've seen in credit markets since the collapse of Lehman Brothers last September, and the sharp rally in stock markets off their March lows is certainly welcomed.

But my extensive travels over the last few months tell me, that there's still plenty of caution to go around.

I've been at several conferences, and when I ask people whether they feel the the sharp rally in equities is sustainable, many are skeptical and believe the markets at some point could retest their lows.

When I asked a group of chief financial officers and comptrollers when they expect a sustained economic recovery, a third of those who raised their hands believe it won't be until 2012 and beyond. And remember, these are the guys holding the purse strings.

As to the other two-thirds of that group, it was divided between next year and 2011.

I've been taking these informal polls since last November, and I'd say the majority of those I ask, believe any sustained recovery won't happen before 2011.

So what's standing in the way? Plenty. Unemployment in the United States and elsewhere continues to rise, consumers are focused on saving instead of spending, housing and commercial property in the U.S. and elsewhere remain under pressure, and banks continue to deleverage.

Confidence of course, is key to any recovery. Even once we get out of negative growth I fear we could bump along the bottom for a quite a while. I am not alone in this fear. I hope I am wrong, but I suspect I will turn out to be right.

 What do you think?