In a bull market, buying on the dips works like a charm. Pullbacks in the market are quickly cannibalized by hungry investors looking for anything that smells like a bargain.

In a bear market, dip-buying does not work so well, as supposed bargains turn out to be value traps. This brings us to Ken Lewis, retiring as CEO of Bank of America. If dip-buying is a disaster in bear markets, Lewis engineered the M&A version of “dip buying” at the worst time not once, but twice.

It used to be that Citigroup was one of the market’s most important stocks, if not the most important. At the nexus of the banking, securities and lending industries that benefited most from the easy-credit boom of the middle of the decade, its success as a stock mirrored the market and the economy.Somewhere around 2006, when people started to call for a breakup of the company, it was supplanted by a company even more tied to the derivative-fueled mess that masked the holes in the economic landscape – Goldman Sachs.

But Goldman continued to earn massive profits while Citigroup nearly died a painful death. Shares eventually fell to less than $1 a share, it was kicked out of the Dow and investors started to view other consumer banks as better indicators of the market’s health.