If I make imagination for both, then I will give an illustration like this:
SEC: a gathering place for traders: markets
ETF: capital or merchant money: Gold, Silver, Berlian, Oil (next Bitcoin).
We can see that SEC has been there before Bitcoin. ETFs are only acquisitions for Bitcoin received in the SEC trading market. Because it's the same as the case with the newly launched exchange that accepts trading pairs with Bitcoin.
In conclusion: It will not have an effect that is too high because the SEC and ETF are not too influential on the Bitcoin trade, maybe the increase in Bitcoin prices is also around 20-30%.