Those behaviors are very common to see, not only in Stellar but in many Altcoins more, those walls are very large, many times the operators do it to protect their established positions and that somehow manipulates the price to absorb the massive purchases, this is for them to buy cheap.

But when observing for a long period of time, many times those walls are removed, and they begin to segment, when they detect that a whale comes in and they react by removing it and putting it in several sale prices, it is very common to see them, that's what it is the market, everyone has their strategy.