The S&P 500 (SP500) flopped into the red for October following a last-day selloff, with the month counting Super Micro Computer (SMCI) among its biggest decliners while United Airlines (UAL) shares sprang up.

The S&P 500 (SP500)(SPY)(IVV) ended 1% lower for the month, rounded off by Thursday's slide of 1.86%, sparked by quarterly updates from Magnificent 7 constituents Microsoft (MSFT) and Meta (META) that failed to impress investors. The index (SP500) logged its first monthly loss since April.

October’s decliners included Super Micro Computer (SMCI), which lost more than a third of its value Wednesday after the AI server company’s auditors, Ernst & Young, unexpectedly resigned.

Qorvo (QRVO) also suffered this week, losing 27% on Tuesday after a downbeat revenue outlook from the connectivity and power solutions company. Moderna (MRNA), hurt by ongoing concerns about slowing demand for COVID and RSV vaccines, posted its fourth monthly decline.

Meanwhile, a number of travel stocks were among the S&P 500’s (SP500) top 10 gainers for October. United Airlines (UAL) stock gained ground after its Q3 financial report surpassed Wall Street’s targets. The airline also announced a $1.5B share buyback program. Raised guidance by Royal Caribbean Cruises (RCL) and Norwegian Cruise Line (NCLH) aided their stock gains.

Here are the top 10 percentage gainers in the S&P 500 (SP500) in October:

• Advancers
• United Airlines (UAL): +40.9%
• Raymond James (RJF): +21.7%
• Carnival (CCL): +19.9%
• Lamb Weston (LW): +19.3%
• Royal Caribbean Cruises (RCL): +17.48%
• Palantir (PLTR): +17.45%
• GE Vernova (GEV): +16.7%
• Garmin (GRMN): +16.4%
• Norwegian Cruise Line (NCL): +16.2%
• General Motors (GM): +15.9%

Here are the biggest losing S&P 500 (SP500) stocks for the month:

• Decliners
• Qorvo (QRVO): -29.3%
• Enphase Energy (ENPH): -27%
• First Solar (FSLR): - 21%
• Super Micro Computer (SMCI): -20.6%
• Teradyne (TER): -18.3%
• AES Corp. (AES): -18.15%
• Moderna (MRNA): -18.12%
• Centene (CNC): -17.9%
• Align Technology (ALGN): -17.1%
• Genuine Parts (GPC): -16.8%