LUDP — LULD pause (5-min)
Limit-Up Limit-Down volatility trip. Often reopens near the halt price; the reopen tape tells direction.
T1 / T2 / H10 — news
News pending or just disseminated. Reopens after the exchange release, often with a gap. Trade the reaction, not the pause.
T12 / H4 — regulatory
Compliance or regulatory suspension. Can last days to weeks and reopen heavily gapped. Binary risk — avoid as a primary entry.
Data: NASDAQ Trader public halt feed via the bpleone worker (~2-min cache). Zero rows means zero current halts on the feed — a normal, real state. Educational, not advice.