Short Term Trading Week Starting: - 22 May, page-62

Here is a question for the experts. Do stop loss's get hit in the closing auction. Just watching a stock and went into 4 pm close at 3.8 cents CSPA was sitting at 3.8 cents then 3.5 and a dump of 569,000 at 3.5 cents closed . Looking at volume after close a small trade went through first at 3.5 cents then the big one. Just wondering whether a stop loss hit or a last minute dump.
Thanks in advance.