As recession fears grow on Wall Street, CNBC Pro found stocks that are cheap even in an economic slowdown. The major averages are heading for a losing week on Friday. Investors are concerned that this week's announcement of the most aggressive rate increase since 1994 by the Federal Reserve could tip the economy into a recession. Stocks may also continue to spiral if earnings estimates come down. This week, Deutsche Bank analysts said earnings estimates are "too high," given their base assumption of a modest recession by the end of 2023. They called out mega cap growth and tech stocks as especially vulnerable to elevated expectations. Still, some stocks may present investors with a " margin of safety " over the long term even in a recession scenario. CNBC Pro lowered the 12-month earnings estimates of every company in the S & P 500 by 30% to calculate the forward price-earnings ratio of each stock in a recession scenario. We then compared the new recession-adjusted forward P/E to the average P/E of the last five years. To be sure, these are long-term investing opportunities to take advantage of in the current sell-off as they should reflect the real value of securities over time. Here are the 20 cheapest stocks in the S & P 500 in a recession scenario: Many energy stocks made it onto the list. Shares of Occidental Petroleum are expected to sell at 8.8 times its earnings after adjusting for recession, meaning it will trade at a 65.7% discount to its 5-year average forward P/E of 25.8. Shares of Valero Energy should trade at at a P/E of 12.2 even in a downturn, at a 54% discount to its 5-year average forward earnings. Shares of Diamondback Energy are expected to trade at 7.9 times earnings in a recession, or at a 33% discount. Alaska Air could be cheap even after estimates come down. Even after cutting earnings estimates for a recession scenario, the airline carrier is expected to trade at 10.6 times its earnings, or at a nearly 63% discount. United Airlines also made it onto the list. The P/E ratio of the airline is expected to be 13.7 in a recession, or at a 45% discount. Some homebuilders also look like buying opportunities in a recession scenario. D.R. Horton has a recession P/E of 5.2, which would be at a 46% discount to the average forward earnings of the last five years. Lennar has a recession P/E of 5.6, a 37% discount. PulteGroup has a recession P/E of 4.7, or at a nearly 43% discount. Other stocks included in this list are Mosaic , Moderna , EOG Resources , Devon Energy , Pioneer Natural Resources , Chevron , Exxon Mobil , PVH , Coterra Energy , Weyerhaeuser , Global Payments and Nucor .