Last week was one of the most chaotic in Wall Street’s history. Several important stocks dropped cataclysmically — namely Fannie Mae (FNM), Freddie Mac (FRE) and Lehman Brothers (LEH) — and Merrill Lynch (MER) and American International Group (AIG) came close to collapse.

For students at Yale, where about 20 percent of each graduating class goes on to be employed by I-banks every year, these developments could be problematic. Many employers of Yale graduates, like Bear Stearns, Lehman Brothers and Merrill Lynch, no longer exist or may not exist for much longer. Other banks, like Citigroup, have drastically shrunk their workforces and are not necessarily eager to employ large numbers of recent college graduates or summer interns.

Lehman Brothers’ precipitous decline began Monday morning. Barely 20 minutes into the trading day, with the Dow Jones Industrial Average up over 250 points, Lehman quietly — and ominously — turned negative on the day. The drop indicated that something was seriously wrong with the company, and Lehman Brothers, after failing to find a buyer over the weekend, began the process of filing for bankruptcy.

Merrill Lynch will not survive as an independent company much longer. The management of Bank of America (BAC) reached an agreement with Merrill Lynch to take over the company.

After Lehman Brothers files for bankruptcy protection and Merrill Lynch is bought by Bank of America, another round of forced consolidation on Wall Street will be complete. This elimination of firms in the financial sector keeps the sector afloat, but many of those who work for these corporations have lost their jobs.

For years, Yale graduates with aspirations for wealth have flocked to I-banks, but now competition for lucrative Wall Streets jobs will become even more intense. Fewer investment banks exist, and those that do will be wary of the expenses they incur by hiring superfluous workers. It certainly seems likely that table 35 at the Yale University Career Fair this Friday, reserved for Lehman Brothers, will be vacant.

Meanwhile Fannie and Freddie, two other financial giants, also suffered big declines Monday because of the announcement that the U.S. government would assume control over them. This move by the government saved them from possible bankruptcy, but, unfortunately for shareholders, the U.S. Treasury Department will not buy Fannie and Freddie common stock for anything near what it was worth just a year ago.

Now that the behemoths of the banking sector are collapsing around us, Yale graduates may have to find a new place to seek riches — at least temporarily.

THE WEEK AHEAD: To some, the stock market’s performance during the past week indicates resilience and Thursday’s huge move upward from the day’s low signals a bottom. This week, however, seems almost certain to start on a down note — the result of Lehman Brothers’ bankruptcy.

For those interested in gaming the market, the most important stocks to watch are American International Group and Merrill Lynch. Now that Lehman Brothers has collapsed, AIG and Merrill are the next “shoes to drop.” In order for the market to begin to recover, the financial sector must safely liquidate Lehman’s assets, AIG must find more capital and Bank of America must safely take on Merrill Lynch’s debt.