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 Crosstex Energy (Nasdaq: XTXI) jumped 10% in intraday trading today after an analyst upgrade.

So what: Yesterday, Morgan Stanley (NYSE: MS) upgraded shares to overweight from market perform. It was also announced that Crosstex would join the Alerian MLP Index (AMEX: ^AMZ.A), replacing Duncan Energy Partners (NYSE: DEP).

Now what: Joining an index can cause a temporary pop for shares as funds following the index buy shares. But the bigger news today was the upgrade from Morgan Stanley, which has driven shares higher. I'm leery of buying on pops because of an analyst, especially from a company losing money every quarter.

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