Why are some of the biggest names in the corporate world unloading stock like there is no tomorrow, and why are some of the most prominent investors on Wall Street loudly warning about the possibility of a market crash? Should we be alarmed that the big dogs on Wall Street are starting to get very nervous? In a previous article, I got very excited about a report that indicated that corporate insiders were selling nine times more of their own shares than they were buying. Well, according to a brand new Bloomberg article, insider sales of stock have outnumbered insider purchases of stock by a ratio of twelve to one over the past three months. That is highly unusual. And right now some of the most respected investors in the financial world are ringing the alarm bells. Dennis Gartman says that it is time to “rush to the sidelines”, Seth Klarman is warning about “the un-abating risks of collapse”, and Doug Kass is proclaiming that “we’re headed for a sharp fall”. So does all of this mean that a market crash is definitely on the way? No, but when you combine all of this with the weak economic data constantly coming out of the U.S. and Europe, it certainly does not paint a pretty picture.\nAccording to Bloomberg, it has been two years since we have seen insider sales of stock at this level. And when insider sales of stock are this high, that usually means that the market is about to decline…\n\nCorporate executives are taking advantage of near-record U.S. stock prices by selling shares in their companies at the fastest pace in two years.\nThere were about 12 stock-sale announcements over the past three months for every purchase by insiders at Standard & Poor’s 500 Index (SPX) companies, the highest ratio since January 2011, according to data compiled by Bloomberg and Pavilion Global Markets. Whenever the ratio exceeded 11 in the past, the benchmark index declined 5.9 percent on average in the next six months, according to Pavilion, a Montreal-based trading firm.\n\nBut it isn’t just the number of stock sales that is alarming. Some of these insider transactions are absolutely huge. Just check out these numbers…\n\nAmong the biggest transactions last week were a $65.2 million sale by Google Inc.’s 39-year-old Chief Executive Officer Larry Page, a $40.1 million disposal by News Corp.’s 81- year-old Chairman and CEO Rupert Murdoch and a $34.2 million sale from American Express Co. chief Kenneth Chenault, who is 61. Nolan Archibald, the 69-year-old chairman of Stanley Black & Decker Inc. who plans to leave his post next month, unloaded $29.7 million in shares last week and Amphenol Corp. Chairman Martin Hans Loeffler, 68, sold $27.5 million, according to data compiled by Bloomberg.\nGoogle Chairman Eric Schmidt, 57, announced plans to sell as many as 3.2 million shares in the operator of the world’s most-popular search engine. The planned share sales, worth about $2.5 billion, represent about 42 percent of Schmidt’s holdings.\n\nSo why are all of these very prominent executives cashing out all of a sudden?\nThat is a very good question.\nMeanwhile, some of the most respected names on Wall Street are warning that it is time to get out of the market.\nFor example, investor Dennis Gartman recently wrote that the game is “changing” and that it is time to “rush to the sidelines”…\n\n“When tectonic plates in the earth’s crust shift earthquakes happen and when the tectonic plants shift beneath our feet in the capital markets margin calls take place. The tectonic plates have shifted and attention… very careful and very substantive attention… must be paid.\n“Simply put, the game has changed and where we were playing a ‘game’ fueled by the monetary authorities and fueled by the urge on the part of participants to see and believe in rising ‘animal spirits’ as Lord Keynes referred to them we played bullishly of equities and of the EUR and of ‘risk assets’. Now, with the game changing, our tools have to change and so too our perspective.\n“Where we were buyers of equities previously we must disdain them henceforth. Where we were sellers of Yen and US dollars we must buy them now. Where we had been long of gold in Yen terms, we must shift that and turn bullish of gold in EUR terms. Where we might have been ‘technically’ bullish of the EUR we must now be technically and fundamentally bearish of it. The game board has been flipped over; the game has changed… change with it or perish. We cannot be more blunt than that.”\n\nThat is a very ominous warning, but he is far from alone. Just the other day, I wrote about how legendary investor Seth Klarman is warning that the collapse of the financial markets could happen at literally any time…\n\n“Investing today may well be harder than it has been at any time in our three decades of existence,” writes Seth Klarman in his year-end letter. The Fed’s “relentless interventions and manipulations” have left few purchase targets for Baupost, he laments. “(The) underpinnings of our economy and financial system are so precarious that the un-abating risks of collapse dwarf all other factors.”\n\nOther big hitters on Wall Street are ringing the alarm bells as well. For example, Seabreeze Partners portfolio manager Doug Kass recently told CNBC that what he is seeing right now reminds him of the period just before the crash of 1987…\n\n“I’m getting the ‘summer of 1987 feeling’ in the U.S. equity market,” Kass told CNBC, “which means we’re headed for a sharp fall.”\n\nAnd of course the “perma-bears” continue to warn that the months ahead are going to be very difficult. For instance, “Dr. Doom” Marc Faber recently said that he “loves the high odds of a ‘big-time’ market crash“.\nAnother “perma-bear”, Nomura’s Bob Janjuah, is convinced that the stock market will experience one more huge spike before collapsing by up to 50%…\n\nI continue to believe that the S&P500 can trade up towards the 1575\/1550 area, where we have, so far, a grand double top. I would not be surprised to see the S&P trade marginally through the 2007 all-time nominal high (the real high was of course seen over a decade ago – so much for equities as a long-term vehicle for wealth creation!). A weekly close at a new all-time high would I think lead to the final parabolic spike up which creates the kind of positioning extreme and leverage extreme needed to create the conditions for a 25% to 50% collapse in equities over the rest of 2013 and 2014, driven by real economy reality hitting home, and by policymaker failure\/loss of faith in “their system”.\n\nSo are they right?\nWe will see.\nAt the same time that many of the big dogs are pulling their money out of the market, many smaller investors are rushing to put their money back in to the market. The mainstream media continues to assure them that everything is wonderful and that this rally can last forever.\nBut it is important to keep in mind that the last time that Wall Street was this “euphoric” was right before the market crash in 2008.\nSo what should we be watching for?\nAs I have mentioned before, it is very important to watch the financial markets in Europe right now.\nIf they crash, the financial markets in the U.S. will probably crash too.\nAnd the financial markets in Europe definitely have had a rough week. Just check out what happened on Thursday. The following is from a report by CNBC’s Bob Pisani…\n\nItaly, Germany, France, Spain, U.K., Greece, and Portugal all on track to log worst day since Feb. 4. European PMI numbers were disappointing, with all major countries except Germany reporting numbers below 50, indicating contraction.\nWhat does this mean? It means Europe remains mired in recession: “The euro zone is on course to contract for a fourth consecutive quarter,” Markit, who provides the PMI data, said. A new insight is that France is now joining the weakness shown in periphery countries.\nYou’re giving me agita: Italy was the worst market, down 2.5 percent. The CEO of banking company, Intesa Sanpaolo, said Italy’s recession has been so bad it could cause a fifth of Italian companies to fail, noting that topline for those bottom fifth have been shrinking 35 to 45 percent. Italian elections are this weekend.\nIt wasn’t any better in Asia. The Shanghai Index had its worst day in over a year, closing down nearly three percent.\n\nAnd the economic numbers coming out of the U.S. also continue to be quite depressing.\nOn Thursday, the Department of Labor announced that there were 362,000 initial claims for unemployment benefits during the week ending February 16th. That was a sharp rise from a week earlier.\nBut I am not really concerned about that number yet.\nWhen it rises above 400,000 and it stays there, then it will be time to officially become alarmed.\nSo what is the bottom line?\nThere are trouble signs on the horizon for the financial markets. Nobody should panic right now, but things certainly do not look very promising for the remainder of the year.