Gotta say there looks to me like there is something duboius about Stamp volumes. What is up with the 49.99 BTC bot that is constantly running there semmingly at a loss for the last couple of weeks ( hard to tell without seeing all the trade data, it might be marginally profitable, but it consistently executes a sell order at a lower price than its last buy order, within seconds, and vice versa, which just looks 'off'). There appears to be  49 BTC bot too (and multiples thereof). To me it, it looks like wash trades to give the appearance of accumulation/activity, and to make it look like this is something other than a VERY low volume rally.
Until I hear a good explanation for these, I dont trust this sudden volume increase, thought the reasons you give are all valid and may account for some of it. TBH, for Stamp to have the volumes they claim, in a VERY quiet market, simply does not look right ...