(Bloomberg) -- U.S. stocks dropped after the biggest rally in nine months spurred speculation about excessive investor optimism. Treasuries stabilized, following a recent spike in yields, while the dollar fell.Technology shares led losses in the S&P 500 as commodity producers and banks rose. Giants Apple Inc., Microsoft Corp. and Tesla Inc. dragged down the Nasdaq 100. Target Corp. slumped on an underwhelming profitability outlook. Rocket Cos., a Detroit-based holding company, soared after a news report that the stock could be a Reddit target for its high short-interest.Bullishness among Wall Street strategists is approaching levels that have already presaged potential trouble for stocks, according to a Bank of America Corp. gauge. The measure assesses the average recommended allocation to equities and is close to triggering a sell signal. Earlier Tuesday, China’s top banking regulator said he’s “very worried” about risks from bubbles in global financial markets.Last week, the correlation between real yields and U.S. equities dropped to its most-negative level in five years. That strong inverse relationship suggests inflation-adjusted Treasury rates have reached a point where further gains could quickly send the S&P 500 lower -- as they feed into steeper borrowing costs and lessen the appeal of other assets. The benchmark gauge of American shares has surged more than 70% from its March 2020 lows.For Bill Northey, senior investment director at U.S. Bank Wealth Management, rising rates are seen as an important element of what’s “giving investors pause at this point in time.” He also noted that they’re relevant when it comes to figuring out the appropriate level of valuations against the stream of corporate earnings.“Did we come too far, too fast in pricing in a strong economy and corporate earnings recovery?” he said.Read: Brainard Says Recent Bond Market Moves Have ‘Caught’ Her EyeThere are some key events to watch this week:U.S. Federal Reserve Beige Book is due Wednesday.OPEC+ meeting on output Thursday.U.S. factory orders, initial jobless claims and durable goods orders are due Thursday.The February U.S. employment report on Friday will provide an update on the speed and direction of the nation’s labor market recovery.These are some of the main moves in markets:StocksThe S&P 500 fell 0.3% as of 2:39 p.m. New York time.The Stoxx Europe 600 Index gained 0.2%.The MSCI Asia Pacific Index fell 0.2%.The MSCI Emerging Market Index was little changed.CurrenciesThe Bloomberg Dollar Spot Index fell 0.3%.The euro increased 0.3% to $1.2087.The Japanese yen was little changed at 106.73 per dollar.BondsThe yield on 10-year Treasuries dipped one basis point to 1.41%.Germany’s 10-year yield dipped two basis points to -0.35%.Britain’s 10-year yield decreased seven basis points to 0.687%.CommoditiesWest Texas Intermediate crude was little changed at $60.61 a barrel.Gold climbed 0.7% to $1,736.97 an ounce.Silver added 1% to $26.85 per ounce.For more articles like this, please visit us at bloomberg.comSubscribe now to stay ahead with the most trusted business news source.©2021 Bloomberg L.P.