Two factors often determine stock prices in the long run: earnings and interest rates. Investors can't control the latter, but they can focus on a company's earnings results every quarter.Life and the stock market are both about expectations, and rising above what is expected is often rewarded, while falling short can come with negative consequences. Investors might want to try to capture stronger returns by finding positive earnings surprises.Now that we know how important earnings and earnings surprises are, it's time to show investors how to take advantage of these events to boost their returns by utilizing the Zacks Earnings ESP filter.The Zacks Earnings ESP, ExplainedThe Zacks Earnings ESP, or Expected Surprise Prediction, aims to find earnings surprises by focusing on the most recent analyst revisions. The basic premise is that if an analyst reevaluates their earnings estimate ahead of an earnings release, it means they likely have new information that could possibly be more accurate.Now that we understand the basic idea, let's look at how the Expected Surprise Prediction works. The ESP is calculated by comparing the Most Accurate Estimate to the Zacks Consensus Estimate, with the percentage difference between the two giving us the Zacks ESP figure.When we join a positive earnings ESP with a Zacks Rank #3 (Hold) or stronger, stocks posted a positive bottom-line surprise 70% of the time. Plus, this system saw investors produce roughly 28% annual returns on average, according to our 10 year backtest.Stocks with a #3 (Hold) ranking, which is most stocks covered at 60%, are expected to perform in-line with the broader market. But stocks that fall into the #2 (Buy) and #1 (Strong Buy) ranking, or the top 15% and top 5% of stocks, respectively, should outperform the market. Strong Buy stocks should outperform more than any other rank.Should You Consider Thermo Fisher Scientific?The final step today is to look at a stock that meets our ESP qualifications. Thermo Fisher Scientific (TMO) earns a #3 (Hold) nine days from its next quarterly earnings release on October 20, 2021, and its Most Accurate Estimate comes in at $4.64 a share.By taking the percentage difference between the $4.64 Most Accurate Estimate and the $4.60 Zacks Consensus Estimate, Thermo Fisher Scientific has an Earnings ESP of 0.79%. Investors should also know that TMO is just one of a large group of stocks with positive ESPs. All of these qualifying stocks can be filtered by ESP, Zacks Rank, % Surprise (Last Qtr.), and Reporting date.Now that you know how to use the Zacks Earnings ESP to your advantage, make sure to check out the Earnings ESP Home Page for even more earnings related strategies to create a winning portfolio.Find Stocks to Buy or Sell Before They're ReportedUse the Zacks Earnings ESP Filter to turn up stocks with the highest probability of positively, or negatively, surprising to buy or sell before they're reported for profitable earnings season trading. Check it out here >> Tech IPOs With Massive Profit Potential In the past few years, many popular platforms and like Uber and Airbnb finally made their way to the public markets. But the biggest paydays came from lesser-known names. For example, electric carmaker X Peng shot up +299.4% in just 2 months. Think of it this way… If you had put $5,000 into XPEV at its IPO in September 2020, you could have cashed out with $19,970 in November. With record amounts of cash flooding into IPOs and a record-setting stock market, this year’s lineup could be even more lucrative.See Zacks Hottest Tech IPOs Now >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Thermo Fisher Scientific Inc. (TMO): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research