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

What: Shares of homebuilder D.R. Horton, (NYSE:DHI) fell 11.6% today after reporting second-quarter earnings.

So what: Net sales orders in the quarter jumped 32%, to $2.4 billion, and revenue was up 28%, to $2.1 billion, but the bottom line deteriorated on discounting. Net income dropped 22.5%, to $113.1 million, or $0.32 per share, well below the $0.49 analysts expected.

Now what: The housing market has been in a long-term recovery, but early in 2014, there are signs of fatigue. Buyers who could afford to get into new homes have already done so, and the labor market isn't leading to a new batch of buyers. Combine that with a large increase in home values during the last year, and interest rates that are higher than they were to begin 2013, and you have companies competing harder for the buyers who are out there. That's why the bottom line looked so bad for D.R. Horton.