Why the difference? Part of the reason is that the Invesco Momentum ETF is a long-only portfolio—it has no short bets that can go against it. The rest of the difference can be attributed to the timing and frequency of its rebalances: The Invesco Momentum ETF rebalanced only twice a year in March and last September, while the earlier-mentioned long-short strategy does it quarterly, the latest ones in February and last November.
The solution to both is investing in stock index funds and ETFs. While mutual funds might require a $1,000 minimum or more, index fund minimums tend to be lower (and ETFs are purchased for a share price that could be lower still). Two brokers, Fidelity and Charles Schwab, offer index funds with no minimum at all. Index funds also cure the diversification issue because they hold many different stocks within a single fund.
The most recent annual report – While reading the annual report, you'll want to pay special attention to the letter from the Chairman, CEO, and sometimes CFO or other high-ranking officers to see how they view the business. Not all annual reports are created equally. Generally, the best in the business is considered to be the one written by Warren Buffett at Berkshire Hathaway, which you can download from free on the holding company's corporate site.
Still, other momentum strategies involve cross-asset analysis. For example, some equity traders closely watch the Treasury yield curve and use it as a momentum signal for equity entries and exits. A 10-year Treasury yield above the two-year yield generally is a buy signal, whereas a two-year yield trading above the 10-year is a sell signal. Notably, the two-year versus 10-year Treasury yields tend to be a strong predictor of recessions, and also has implications for stock markets.