I disagree. Looking at the time stamp, two trades went through at 3:25, with the first one of 702 shares and the second of 5000 shares. The same time stamp on both means that a single buyer bought both lots and it is probably the same person who is now bidding for ca. 19k shares at 10.5 (his order got only partially filled).
The reason the last trade was for 5000 shares was not because somebudo is trying to manipulate the price, rather it's because that's all that was available (there were two sellers in total at 10.5, with the first offering 702 shares and the second offering 5,000 shares).
Contrary to the way you're looking at it, I think today's indivdual trade sizes have been fairly decent compared to past few days.
AXT Price at posting:
10.5¢ Sentiment: None Disclosure: Held