When polo went above 2000 it became way ahead of btc38. The 'dumping' could easily have just been arbitraging.

EXACTLY!
that is my observation too for many big transfers to poloniex.
When poloniex price is above btc38 price, millions of BTS go to poloniex.
It is in most cases arbitraging!! Good call
@Ander !!!
PS and it helps because the fund are in seconds on the exchanges....
