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 diversified holding company Leucadia (NYSE: LUK) were getting hammered in early trading today, falling as much as 13% in intraday trading on the market's concerns over Jefferies Group (NYSE: JEF).

So what: As the largest shareholder in Jefferies Group -- with roughly a quarter of outstanding shares as of the latest numbers -- it's no surprise that investors might knock down Leucadia's stock along with Jefferies'. And, likewise, there should be no shock that Leucadia's stock recovered as emotions cooled and Jefferies started to float back toward even.

 Now what: Leucadia is overseen by savvy investor Ian Cumming, and the company has apparently determined to not sit on its hands while the market heaps doubt on Jefferies' viability. According to a regulatory filing released today, Leucadia upped its stake in Jefferies by another million shares yesterday. For investors who believe that Jefferies is sound, the question now may be whether to jump directly on the beaten-down Jefferies shares or grab the diversified investor in Leucadia that's looking to capitalize on the lower-priced stock.

Want to keep up to date on these companies?