I've heard that there are fails to deliver, more so in certain stocks than others. Some say its just because brokers don't communicate etc, but some people like deepcapture.com suggest this is evidence of intentional manipulation down by Market Makers and the failure to deliver acts as a kind of endless selling which is commonly called "naked shorting".
Naked short will be a foot note in stock market history books. Fer chrissakes a legit short is eating stone soup these days.
yeah naked shorts are going to be inevitable as long as there are market makers and leverage. it's only natural. whenever i'm long and a stock takes an unnatural dip and then right back up to the original price, i don't blame my analysis i believe it's the market makers making a killing because the sell volume cant drop a price that quick