We only know some odds, which ultimately are not reliable as we have seen in the past with brexit and trump events with odds against those events.
So it's a gamble: ETF or no ETF? sell and buy back cheaper, or hold and see your BTC go $3000?
I have no idea, it all comes down to luck, so good luck to you (and to me)
its too much prediction on what will happen after ETF and i am sure that no one can make the right prediction as the price is followed by traders on the market. so i think as long as we can make good profit with the price now and after ETF, no matter the price is down or up, we can follow the market and we still can make profit with that. but if we only want to make profit at least in $3000, we can hold it for a while and waiting until we can see the price that we want.