DOW FUTURES DOWN 300

US markets are getting slammed right now.

Dow futures are down Dow futures are down by a whopping 300 points right now. S&P futures are down 26 points

This follows disappointing earnings announcements from corporate giants Caterpillar and Microsoft.

The just-released December durable goods report was very disappointing. Orders unexpectedly plunged by 3.4%. November's number was revised to -2.1% from last month's -0.7% estimate.

Capital good orders excluding nondefense aircraft fell 0.6%, missing economists' expectation for a 0.9% gain.

Weighing On The Dow

The 30-component Dow Jones Industrial Average is a peculiar stock market index for several reasons.

For one, it's a price-weighted index, which means a stock with a high per-share price will have a greater influence on the index's fluctuations. And currently, a one-point move in any single Dow stock moves the Dow by 6.42195 points.

Currently, four stocks are tumbling after releasing quarterly earnings and guidance that fell short of expectations: Microsoft, Caterpillar, Proctor & Gamble, and United Technologies.

• Microsoft is down 3.6 points (-7.6%), which shaves 23.1 points from the Dow.
• CAT is down 6.1 points (-7.1%), which hacks 39.1 points.
• United Technologies is down 3.2 points (2.7%), which cuts 20.5 points.
• P&G is down by 2.3 points (2.6%), which takes 14.7 points.

Altogether, that's 97.4 points.