We might keep drifting down for a little while, but as a general rule I feel that these sell walls represent a buying opportunity. I say that because if I were honestly trying to unload coins rather than just manipulate the price then I'd do it piecemeal in several smaller bids so as to have as minimal an impact on prices as possible (and it is also quicker because you don't get front ran so much by panic sellers). So, unless these sell wall guys are complete idiots, there seems to be market manipulation. The manipulation has a downward, not an upward, impact on prices making coins cheaper in a way that they know and that enables accumulation (and even if some of their coins get bought out from them, there are still more people front-running their walls and other exchanges responding to the impact of the walls on the one exchange, for them to pick up more coins in small increments). Ergo, whenever I see these things I interpret it as a buying opportunity as the only reason why somebody would be doing it (absent it being government level manipulation which it doesn't appear to be... it would be thousands rather than hundreds of coins) is because they think the true valuation of the coin is higher than where they set the wall.
Could they get dicked over doing this... perhaps, but not at this volume level. Anyhow, I am fairly new, but this strategy has yet to fail me over the past two months... I buy into these sell walls every chance I get.
Thus, maybe I'd sell if I were you if you expect this to go on for a little while longer, but I'd have an eye towards jumping right back into the game soon.