Today, the Dow Jones Industrials (^DJI -0.22%) commemorated the 25th anniversary of the Crash of 1987, by dropping more than 200 points. With a confluence of bad earnings reports coming from several Dow component stocks, investors have had their fears reawakened that the long bull market in stocks, since the lows of early 2009, may finally be coming to an end. It was the biggest drop for the average since mid-June.

Only a single Dow stock, Home Depot (HD -2.06%), managed to post a gain today. The National Association of Realtors said that existing home sales fell 1.7% in September, but that the price of homes sold jumped by the largest amount in seven years. With its shares having jumped so much already, it's unclear how much further Home Depot can climb, even if recent good news from the housing market continues.

Bank of America (BAC -0.16%) managed to limit its losses to a third of a percent. As Fool contributor Anders Bylund noted earlier today, B of A has taken steps to reduce mortgage principal balances on loans it made, with roughly $4.75 billion in reductions taken thus far. With New York Fed Chairman William Dudley pointing to concentrations of mortgage origination at a few banks, which include B of A, Citigroup (C -0.73%), and several others, the bank really needs to put the housing crunch behind it if it wants to build its profits back up to their full potential.

Finally, Boeing (BA -1.30%) lost about a third of a percent, as well. Unlike many businesses, Boeing already has more than enough customers to handle for years into the future. What it needs to do, though, is serve those customers, by getting planes built and delivered in a timely fashion. If it can do that, Boeing should hold up well in just about any economic environment.