ETFs (Exchange Traded Funds) is funds (pooled investment) traded on the exchange. This is liquid security (can be easily converted into cash). This is security (usually part) that only tracks indices a basket of stocks or commodities.
A full SEC approval will literally kick the door for traditional investors who want to diversify and put their hands on a market that offers relatively high profits and that will make them want to pour large amounts of cash into ETFs and put a portion of it. directly to Bitcoin itself.
This will cause a price increase, it should. It sounds too simple to be true, but that is what will cause the extraordinary demand for Bitcoin that comes with limited inventory, in turn, will result in a price spike until market forces find balance.