ETF approved - $2000-$3000 in the short term. Continues to clim as more and more money comes in.
ETF declined - $800 within a week. Slow climb from there on until the next hype bubbl
Either way, in the long term BTC has everything it needs to reach $10k so you keep HODLing.
It's about hundred million dollar and not about billion dollars will go to the bitcoin. And $2000 - $3000 really impossible for the bitcoin to reach that range as soon as possible. The declined of ETF will bring the price of bitcoin into above $1000 but not for the below $1000.