How a momentum stock scanner works: from 5,000 stocks to a short watchlist

There are roughly five thousand stocks listed in the US. Nobody can look at all of them every evening, and most of them aren’t doing anything worth studying on a given day. A stock scanner does the first pass for you: it applies the same filters to every stock, every day, and hands back the few that pass.

That last part — the same filters, every day — is the whole value. A scanner doesn’t have opinions, moods or a position it’s hoping you’ll buy. It also doesn’t know about the news, the chart pattern’s context or your account. It narrows the search; the judgment is still yours.

The first filters remove stocks that are hard to trade well, whatever their chart looks like:

• Price above about $10: very low-priced stocks move in jumps and attract manipulation.
• Market value above about $1 billion: a real business with real buyers and sellers.
• Enough volume: at least a million shares a day, and ideally $20 million or more traded. Thin stocks fill badly, and stops in them slip.
• A wide enough daily range: a stock that moves 1% a day can’t make a swing trade worth the risk. The Hub’s breakout scan asks for an average daily range of 3.5% or more.

Momentum scanners look for stocks that have already shown strength, because strong stocks tend to attract the buyers that make breakouts work. A common filter is the three-month return: the Hub’s scan starts from stocks up 30% or more in three months, sorted strongest first.

This is the step that surprises people: a momentum scanner deliberately ignores “cheap” stocks that have fallen. It is not looking for value; it is looking for stocks that buyers are already chasing.

A stock that ran 40% this month is interesting, but you can’t buy it responsibly in the middle of the run: there’s no nearby level that tells you you’re wrong. So the last filter is a setup check: has the stock paused in a tight range (a flag) or pulled back to a rising moving average, with the 10-, 20- and 50-day averages stacked and rising?

Those checks turn a list of strong stocks into a short list of strong stocks with a defined trigger and a defined stop. That’s what the evening watchlist is.

• Earnings: a stock that reports in the next few days can gap straight through any stop. The Hub’s scan drops names with earnings in the next five trading days, and its posts skip names that reported yesterday or today.
• Too many of one kind: biotech stocks move on trial results and FDA decisions, more like a coin flip than a breakout. The list caps how many it carries.
• The market: when the index and most sectors are weak, most breakouts fail. Sector rotation is a tie-breaker that puts names in leading groups first.

Treat each name as a question, not an answer. Open the chart. Is the flag really tight, or is it a messy range? Is there news? Is the stock’s sector leading or lagging? Where exactly would you be wrong, and how many shares does that allow at the risk you can afford?

Most names on any watchlist never trigger, and many that do will fail. That isn’t a broken scanner; it’s how breakout trading works. The edge, if there is one, comes from small defined losses on the failures and letting the few that work run.