I had been asking this question for some time.
Being new to the trading scene, this did not make any sense to me. Why would anyone want to make a trade where the would get less from the sale of the stock that they paid in commission fees.
The answer will explain some (if not all) of these "micro trades".
If an investor in the stock market had purchase WM back when it had a reasonable value (say over $10 per) 100 shares would have been a decent size transaction. Now, if that same trader has made some profit on transactions from other investments that have been realized so far this year, they can sell the Wamuq stock at a loss to reduce their total gross profit from trades for this year. As the commission is counted against the gross profit, there is no real concern for this cost in association with the share price for realizing this loss to reduce realized gains.
I still find it hard to believe that there are that many individual investors out there that need to sell off 100 shares of Wamuq to realize a loss as that would indicate that in the present market they had managed to realize a profit from their other transactions as well.