Until the fiscal cliff is resolved Zillow will continue to go lower.
The smart money is not willing to commit any money towards ANY stocks until the fiscal cliff is resolved. It will create an excellent buying opportunity in December. So get completely in cash and wait for the cliff's resolution and then watch the market soar. (probably just before Christmas.)
That is the risk.... PCLN dropped 90% during the 2001 recession stayed down for years. EXPE dropped over 80% during the 09 recession.
Large Short position.... No uptick rule to prevent fast slide.... unfortunately Hedge Funds can drive stock prices down without an uptick rule. Housing is cyclical...this seems to be advertising revenue model... Both GOOG & YHOO dropped significantly in 09' recession