Not wearing any tinfoil hat here, but too many coincidences in order to move the price down looks fishy to me.
You don't need a tinfoil hat to realize that pretty much every time there's volatility or significant movement in XMR's price, some kind of major disruption/panic occurs to thwart it. Every single time.
who ever is dumping now is doing us a service, the number of coins the XMR emission gave us the past year will now take 2 years

Markets are the ultimate contrarians; when everybody expects XMR's price to increase (irrational exuberance) it will always go down.
This is counter-intuitive, probably because our mammal monkey brains are not wired for Baysian filtering, and thus don't properly discount spammy price-hyping bias confirmations.
The new ability to short XMR acts to price in future emission and thus flatten demand peaks, sometimes to the point of trend-breaking technical damage.
In the longer term, this effect will be mitigated by the countervailing fact that XMR lending is removing tens of thousands of coins from the sell side, and by the inevitable short squeezes.
TL;DR: Dear Mr. XMR Dumper, please borrow and dump moar XMR. They still
are seem too expensive for my cheapskate early-adopting ass to nobble and HLOD.