There are three things that are possibly going to occur if bitcoin ETF will be approved by the Securities and Exchange COmmission. The first is that bitcoin may increase in value because of the good news, 2nd is that bitcoins value will decrease in value or 3rd there will be no effect. So today what we have is only a possibility but we will see what will really happen only after it was approved.
I disagree. there is only one possibility, price will definitely increase in case ETF is approved by the SEC. and it won't be because ETF is a good thing or anything like that but it would be because of Fear Of Missing Out and pure speculation that bitcoin should rise because ETF was approved!
it doesn't have to even make sense, people have to believe in it and then act on this speculation for the price to go up. of course there is positive sides to such approval by SEC too but that will be more of a long term effect.