Unusual pre-market often indicates that institutional market makers are moving the market, which is a good sign for unusual high price movement.
The indicator helps me to spot stocks, if a pre-market gap is confirmed with enough (unusual) .
You can define, what "unusual" means by you, by adjusting the length and the multiplier.
The default is a length of 21 bars and a 2.5 multiplier, meaning I'm interested in a stock, if the pre-market exceeds the average pre-market by 2.5 times.
In true TradingView spirit, the author of this script has published it open-source, so traders can understand and verify it. Cheers to the author! You may use it for free, but reuse of this code in a publication is governed by House Rules. You can favorite it to use it on a chart.
So this is not a buy / sell signal indicator. It just helps to pick the right stocks for intra-day trading.
You can use this together with pre-market / opening gaps. A gap with high pre-market volume is more reliable.
I'm using this to create my daily watch list and then I look for entry signals on these stocks.