U.S. stock markets were closed Monday for Martin Luther King Jr. Day, pausing trading after a volatile end to last week. The S&P 500 finished its last session before the holiday at 6,940.01, down 4.46 points, or 0.06%, according to market data. The early close left investors digesting fresh trade headlines and planning for when trading resumes. The question many investors are asking remains direct: is the stock market open on MLK Day? The answer is no. Both the New York Stock Exchange and Nasdaq observe the federal holiday, halting equities trading for the day, as outlined by market notices and holiday calendars cited by Rolling Out, INDmoney, and Barron’s. Is the stock market open on MLK Day? Holiday schedule explained U.S. equity markets close each year on Martin Luther King Jr. Day, one of several federal holidays recognized by major exchanges. While stock trading stops, some financial services continue to operate on limited schedules, and futures markets may follow modified hours. Bond markets also shut down for the holiday, adding to the overall pause in U.S. financial activity. Banks often remain open with adjusted hours, while government offices and the U.S. Postal Service close, depending on the institution. Because markets close for the entire day, no regular-session price discovery occurs. As a result, developments over the long weekend can feed directly into price moves when trading resumes. S&P 500 close, Trump tariffs, and what happens when trading reopens The S&P 500 ended the prior session slightly lower after intraday swings, as shown in the accompanying chart. The index traded within a range near recent highs before dipping into the close, reflecting cautious positioning ahead of the holiday. That caution increased after reports of new tariffs announced by President Donald Trump, targeting additional European Union goods, alongside potential EU countermeasures on U.S. exports. The renewed tariff rhetoric revived concerns about trade friction between the U.S. and Europe, a factor that has historically weighed on equities tied to global supply chains. Markets are set to reopen on Tuesday, following the MLK Day holiday. When trading resumes, investors will assess how tariff developments, global market moves, and accumulated weekend news affect risk appetite. With no trading buffer on Monday, price reactions could appear quickly at the opening bell as participants reprice positions after the pause. S&P 500 Tests Long-Term Support as Technical Signals Draw Focus A technical chart shared by market analyst CycleBull showed the S&P 500 pressing into a long-term upward trendline, a level that has guided the index since last spring. The visual highlighted repeated rebounds along the same rising support before the latest move dipped through that area, raising attention among chart-focused traders. The chart, created on TradingView, traced the index’s steady climb from an early-year low through a series of higher highs and higher lows. That structure remained intact for months, even during periods of sharp pullbacks. However, the most recent price action appeared to break below the trendline, a shift that technicians often flag as a potential change in momentum rather than a single-session anomaly. CycleBull framed the move as a moment of uncertainty rather than confirmation, noting that major market transitions often begin when long-held technical levels give way. In that context, the chart suggested the market has entered a zone where prior support no longer offers clear guidance, leaving direction more dependent on follow-through and broader conditions.