My colleague Ellen Egeth noted Monday there was an unusual spate of downgrades, and that trend continued Tuesday. I suspect this is because analysts are finally starting to get concerned their second-half estimates are too high and are beginning to adjust. Look what happened today in several key sectors overnight: Banks Ahead of the flood of bank earnings that start on Thursday, Citigroup is adjusting target prices. The firm is downgrading Regions Financia l, launching negative catalyst watches on Keycorp and PNC , and upgrading JPMorgan. Like many, analyst Keith Horowitz is concerned earnings estimates may be too high: "While higher interest rates are a clear positive for bank returns, investor sentiment remains negative due to concerns that Fed action will lead to large credit losses (not reflected in consensus estimates), potential breaks in financial plumbing, and the wildcard of additional regulatory action raising capital requirements," he wrote in a note overnight. Retail Wells Fargo downgrading Gap , as the CEO has resigned, cutting the price target to $10 from $16. Airlines Susquehanna downgraded JetBlue , though it upgraded Southwest . Analyst Christopher N. Stathoulopoulos noted that he expects positive comments from airlines early in this quarter, but that this will change as consumers contend with higher air fares and outsized inflation in general. "While the stocks will likely rally on upbeat outlooks, we believe a 'clearing event' is needed to get the stocks working again; specifically, downward revisions to FY22 and FY23 guidance for capacity..." Delta Airlines CEO Ed Bastian will be on CNBC tomorrow morning to talk about his company's earnings and outlook. Railroads Norfolk Southern and Union Pacific were downgraded at JPMorgan Chase based on persistently weak operations and lower economic forecasts. Housing Lennar was downgraded to neutral from overweight at JPMorgan, which said the industry faces a number of headwinds including softening sales and higher incentives. Metal/energy weakness continues In the first quarter, commodities were the darlings of the market. Oil companies were raking in oceans of cash. They're still raking in oceans of cash and record profits, but the buyer enthusiasm that drove energy stocks up 60% and metals stocks up 50% between January and April has now abated. Commodity ETFs: Bloom off the rose? (% off 52-wk. highs) Energy ETF ( XLE ) 24% Metals ETF (XME) 37% Commodities themselves are also notably weaker. The Invesco DB Base Metals ETF ( DBB ), a basket of aluminum, copper and zinc futures, peaked between March and April and is now 31% off its high. Individual commodity futures have also followed a similar pattern, peaking earlier this year and seeing significant downturns in the past month or so: Commodities: Bloom off the rose? (% off 52-wk. highs) Lumber 52% Wheat 38% Corn 24% Crude Oil 24% Of course, bulls looking for some signs that inflation is starting to top are delighted to watch these declines, since commodities and oil in particular have become proxies for inflation.