It's probably nothing to worry about, some people may be inpatient after they waited for the 60k shares to sell out, they may have expected the price to raise faster or more and when it diden't happen "fast enouth" one or a few people sold off a few shares or it may have been someone that needed a certain amount of btm/btc that checked what options they had to free up capital they had invested in stocks and where they would loose the least by selling off a positions they had invested in, such things happens all the time on different bitcoinshares, people sell shares at pricelevels that don't match the value of the stock.