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 ceramic body-armor manufacturer Ceradyne (Nasdaq: CRDN) shot up 12% Monday morning, profiting from news of a big Defense Logistics Agency armor-buy.

So what: DLA signed on for a three year, indefinite delivery/indefinite quantity (IDIQ) contract for the purchase of Ceradyne's successful "ESAPI" body armor. And while this all sounds rather "indefinite," in fact the first tranche of the order is both defined, and big -- $127 million big.

Now what: At 12 times earnings, and  with more than a third of its market cap in cash, Ceradyne's stock looks attractive if it can just keep the growth up. Today's contract helps to reassure investors that analysts' 14% estimate for Ceradyne's long-term growth rate is achievable -- and that the stock's really as cheap as it looks.

Can Ceradyne keep the contracts coming, and prove the "long-term" part of Wall Street's long-term growth target? Add it to your Fool Watchlist and find out.

Fool contributor Rich Smith does not own (or short) shares of any company named above. We Fools don't 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.