I notice that insiders have been selling lately.
One possibility that's been given is that now that the stock is down, people Are selling so they can realize losses for tax purposes, which suggests it might start going up after the end of the year. But that doesn't explain the insiders, who are cashing in options at early strike prices and realizing profits which are still large.
The NYT, WDJ, and other media have suggested people have started to re-evaluate LC's prospects. Before it was assumed (as typical for a dot-com company) that it would inherit most of the market it was creating. But now it appears it may be facing intense competition, and may not end up dominating the market it helped create. Finally, and probably not least, it has been investing heavily in expanding, which means it has been taking losses. But Wall Street's thinking is very short term. People want to see profits now, or they sell and go for something else.