I've noted many times that much of the explosive rise in the S & P 500 after Covid occurred because profit margins dramatically expanded, from roughly 11% to over 13%. Simply put, during Covid corporations dramatically cut back on spending (for labor, travel, real estate) while increasing efforts to improve efficiency (using technology). Then, when the economy rebounded and revenues increased, more of the revenue went straight to the bottom line. That's called operating leverage. While margins are still strong, they are starting to shrink: Q1 2022 margins were back to 12.0%, according to S & P Global. S & P 500 profit margins Q1 2022 12.0% Q1 2021 13.0% Q1 2020 5.8% Q1 2019 11.2% Source: S & P Global Goldman Sachs says margins are going to slip even more. "Profit margins for the median S & P 500 company will likely decline next year whether or not the economy falls into recession," Goldman senior strategist Ben Snider said in a note to clients Monday night. How much? It depends on whether you believe a recession is coming: "Based on our economists' forecasts, our model points to a 70 [basis point] margin decline for the median S & P 500 company in our non-recessionary baseline and a 130 bp compression in a recession scenario," Snider said. Night trading? There's an ETF for that One of the marvels of modern investing is the ability of exchange-traded funds to exploit virtually any investment fad that comes along. In the last 10 years, we have seen cannabis, crypto, thematic tech, clean energy. We have ETFs for space exploration ( UFO ), livestock ( COW ) and Millennials ( MILN ). Recently we have a climate disaster ETF ( FEMA ). Today, in the latest of niche ETF products, we have a night trading ETF. NightShares, a new entrant to the ETF space, is today launching its first two ETFs: the NightShares 500 ETF ( NSPY ) and the NightShares 2000 ETF ( NIWM ). According to the press release, these ETFs seek to capture value from the "Night Effect," a phenomenon whereby overnight markets have historically outperformed the daytime trading session on a risk-adjusted basis. The NightShares 500 ETF seeks to return the night performance of a portfolio of 500 large-cap U.S. companies. The NightShares 2000 ETF seeks to return the night performance of a portfolio of 2000 small-cap U.S. companies. It's led by Bruce Lavine, a respected industry veteran formerly at Wisdom Tree. "An extensive body of research over many years has shown that investors frequently benefit from avoiding the volatile day sessions and investing in the period between market close and market open," the company's website states. Maybe, but there is also literature about how thin after-hours trading can be, and about wider bid-ask spreads. Be interesting to watch this one.