Remember all those gains the Dow Jones Industrial Average (DJINDICES:^DJI) recorded earlier in the week? The Dow sure doesn't. As of 2 p.m. EDT, the index has plummeted 209 points, or 1.55%, giving back all the feel-good optimism from earlier this week. Stocks across the board are in the red -- so much that every single stock on the index is struggling through losses. This certainly wasn't how investors wanted to end the week, but let's see what you can take away from today's poor performance.

Bad news everywhere
The market got off to a bad start this morning when September sales of existing homes dropped 1.7%. That was bad enough, but as prophesied, the grim reaper has finally come to visit third-quarter earnings season. A few major reports from Dow stocks brought down the entire index. On the NYSE today, 11 stocks have fallen for every three in the green.

McDonalds (NYSE:MCD) dropped the market nuke today with a flat-out bad quarterly report. Same-store sales for the fast food giant advanced at their slowest rate in the post-recession era, while earnings fell below expectations, with analysts pointing toward tougher annualized growth going forward for the company. As a result, the stock has plunged 4.1% so far today to lead all Dow laggards.

Earnings blues didn't stop there. General Electric (NYSE:GE) didn't fare much better, as the diversified conglomerate missed revenue estimates despite hitting net profit projections. With the company expecting little help from the global economy in 2013 and currency woes hurting the balance sheet, the stock has so far dropped 3.3%. GE ended up taking down the entire manufacturing sector with it: so far Caterpillar (NYSE:CAT) has lost 3.2%, and Alcoa (NYSE: AA) has lost 1.9%.

To round out a day of losses, Microsoft (NASDAQ:MSFT) ended up reporting a poor quarter last night, and its stock has paid the price. Shares of the software giant are down 3%, as net income and revenue plummeted in the release. Fortunately for Microsoft shareholders, the company's reported sellout of one model of its Surface tablet and impending release of the Windows 8 operating system could mean that today's setback is only temporary.

A bitter end to the week
Bank of America
(NYSE: BAC) and Home Depot (NYSE: HD) have managed to keep losses to a minimum today and were briefly up earlier, but on the 25th anniversary of the 1987 stock market crash, today's Dow has investors seeing red.

Dan Carroll has no positions in the stocks mentioned above. The Motley Fool owns shares of Bank of America, General Electric Company, McDonald's, and Microsoft. Motley Fool newsletter services recommend The Home Depot, McDonald's, and Microsoft. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.