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 cement maker Martin Marietta Materials, (NYSE:MLM) jumped 10% today after reporting better than expected earnings.

So what: Net revenues jumped 57% from a year ago, due in large part to the acquisition of Texas Industries. Net income was up a whopping 78% to $64.0 million, or $0.95 per share, well above analysts' estimates of $0.82 per share in earnings.  

Now what: There's so much demand in Texas and California that Martin Marietta has announced $10 per ton price increases in those markets. This year, management also expects the aggregates product line to increase shipments 10%-12% over 2015. To top it all off, the board of directors approved a 20 million-share repurchase program.

Operations are definitely headed in the right direction but I'm not seeing enough value to jump in today. Shares are trading at 26 times forward earnings and, in a boom and bust building market, that's not a price I'm willing to pay at what could be the peak of the market.