Session brief · Thursday, September 17, 2026 close

Stocks rose. 3,076 rose, 1,886 fell — but communication services lagged.

8 of 11 sectors finished higher. Technology led at +1.96%; Communication Services lagged at -1.93%.

The biggest liquid gainer was Paradium.AI (PAAI), up 271.2% in communication services.

Among benchmarks, QQQ (Nasdaq-100) did best at +1.73% and IWM (Russell 2000) did worst at +0.53%.

Written from 5,117 common stocksSource: Massive / Polygon daily aggregatesHow the brief is written
Market breadth
5,117 common stocks · previous-session close
▲ 3,076 advancing (60.1%)155 unchanged▼ 1,886 declining (36.9%)

Sectors, cap-weighted

SectorChangeRisingFalling
Technology+1.96%410205
Healthcare+1.07%562274
Materials+0.88%16880
Consumer Discretionary+0.84%314231
Utilities+0.72%7939
Energy+0.46%6955
Industrials+0.38%230179
Real Estate+0.35%13185
Consumer Staples−0.09%5752
Financials−0.16%399347
Communication Services−1.93%5072

Benchmarks

FundCloseChange
SPYS&P 500762.60+1.13%
QQQNasdaq-100716.92+1.73%
IWMRussell 2000285.43+0.53%
DIADow 30518.35+0.61%

Top gainers

Top losers

Most active

Common stocks · $2+ · 500K+ shares · $100M+ market cap · previous-session close. Changes compare the Sep 17, 2026 close with Sep 16, 2026; stocks with unexplained price jumps are excluded.

Stock Market on Thursday, September 17, 2026: What Moved | Gainbot