Although we don't believe in timing the market or panicking over daily movements, we do like to keep an eye on market changes -- just in case they're material to our investing thesis.

Ordinarily, dour economic data can have a depressing effect on the stock market. Yet even after the Commerce Department said that housing starts in the U.S. plunged by 16% last month, their biggest drop since early 2011, the Dow Jones Industrials (^DJI -0.11%) had posted a gain of 72 points as of 11 a.m. EST. Home improvement retailer Home Depot (HD -1.77%) dropped slightly on the news, but gains from energy giants Chevron (CVX 0.44%) and ExxonMobil (XOM 0.02%) outweighed the downward impact from Home Depot's modest decline.

As we've seen with a number of other readings on the economy lately, weather almost certainly played a big impact on January's housing starts numbers. Even though seasonal adjustments already take into account the usual weather patterns that discourage starts in the winter months, last month's particularly cold temperatures appeared to play a particularly big role in the Midwest region, where starts fell by more than two-thirds. Yet a jump of more than 60% in the Northeast challenges that theory, and drops in other areas of the country where weather played less of a role point to underlying housing weakness.

Home Depot's drop of 0.8% follows a similar decline yesterday after sentiment among homebuilding companies plunged in February, according to the National Association of Home Builders. Weather was a factor there, too, but a lack of skilled labor and availability of building materials also created concerns about the state of the industry. Home Depot has a good mix of business from both contractors and homeowners, and anything that threatens its contractor business could undermine the impressive growth the stock has produced in recent years.

On the energy front, though, Chevron jumped 1.8%, while ExxonMobil climbed 0.7%. Prices of both crude oil and refined products have been on the rise lately, as high winter-related demand has started to impact longer-term projections for supplies. Some weather experts expect continued cold conditions in March, and that could lead to a delay in the point at which suppliers stop drawing down their stockpiles and start rebuilding them for the next season. Refiners are particularly benefiting from that trend, and with Chevron and Exxon both retaining their integrated refining operations, they stand to benefit somewhat here. In the long run, though, the question is whether the market will support $100 oil and $5 natural gas, as both companies' production divisions represent the biggest part of their revenues.