Please let me know the screnner “Top Loser of the Day” is for buying opportunity or Selling opportunity?
Hey Thilagar, welcome to the community 
“Top Losers of the Day” is primarily a discovery screener, not a direct buy/sell signal by itself.
The backtest currently assumes long-only setups. So in that context, “Top Losers of the Day” is tested more as a potential buying opportunity discovery screener rather than a short-selling screener.
That said, traders can still interpret and use it differently based on their strategy.