Core terms
Limit Up (LU)
In U.S. intraday equity trading, LU commonly refers to the upper side of the Limit Up/Limit Down price-band mechanism. A band indication is not itself a confirmed trading halt.
What traders should verify
Check the current upper band, quote timestamp and exchange status. An upper Limit State occurs when the national best bid equals the upper band; a pause depends on the plan’s state and timing rules.
Do not conflate
LU is not a fixed daily percentage cap from the previous close. U.S. equity bands use a moving reference and applicable parameters; check platform-specific abbreviations and other markets separately.