Define the filter objective
A screener is not an automatic stock picker. It narrows the universe around a question: liquidity, yield, size, movers, or sector exposure.
Start broad, then narrow
Begin with few criteria, then add volume, market cap, or performance filters. This shows which constraints really matter.
Do not confuse signal and conclusion
A screener highlights candidates. The next step is reading the company page, filings, volume, and peers.
Save useful screens
Recurring screens for active stocks, high yields, large drops, or sector moves make monitoring more consistent.
Check missing data
Missing ratios or filings reduce comparison confidence. Official documents can often complete the picture.