For most of my career, I’d have told you to buy an index fund.

I believed markets were efficient for most of my trading years — that prices already reflect everything worth knowing, and beating them over time is close to impossible.

Experience mostly confirmed it: beating the market is genuinely hard, and hardest of all for someone doing it around a different full-time job. For most people, a low-cost index fund is still the right answer.

Still, I am the kind of person who has to know why something happens. So I kept pulling at the question underneath everything else: why does a stock price actually rise?

For a long time I had the answer backwards. I thought you simply bought great companies.

But every price is a forecast, and a stock rises when the company beats it. The return is the mismatch — the gap between what the market expected and what actually happened.

The factor research is fifty years of published evidence on where those forecasts go wrong. Value, momentum, quality, revisions — measurable traits that have separated strong stocks from weak ones decade after decade, because the human errors behind them repeat.

The evidence comes with costs attached: volatility, long stretches where the method lags, and holdings nobody has heard of. Those costs are probably why it keeps working — returns that were comfortable to earn would have been competed away decades ago.

Ticker Nerd is that evidence run as a full-time job: one model rescoring roughly 4,600 US-listed stocks every day, one portfolio built by rules, every rule published, and my own money in the same book. Verify me on LinkedIn