I think Alibaba is a much bigger deal than FB, simply because of China!
Hisah the S&P is at almost 2000 level, just five years ago it was at 800 levels, don't fight the market! I don't think its a sellers market, I think some stocks are buy while most are holds, for the longterm. Back to Alibaba, I think it will be a buy a couple of weeks after IPO when the excitement dies down or hopefully they have a botched IPO. I just found out that Yahoo owns 22% of the stock, so another alternative is to hope tech stocks crash ( hopefully your doom news of market crash come to pass), that would be the perfect time to get in.