Reading ATR Expansion Cycles Before They Peak
Average true range compression often precedes regime change by several sessions. The mistake is treating the first green ATR bar as confirmation rather than as a cue to watch for follow-through.
In January 2026, a mid-cap industrial name on the SET showed ATR rising from 1.2% to 1.8% of price over four days while price itself moved less than one percent. Traders who waited for a two-percent daily candle entered near the expansion peak rather than at the base.
A practical filter: mark the twenty-day ATR low, then require two consecutive closes with ATR above the five-day simple moving average of ATR before adjusting size. This lag deliberately sacrifices the first bar of expansion in exchange for fewer false starts.
During our Khlong San workshops we annotate these sequences on paper first before transferring marks to screen. The physical step slows impulsive entries and gives time to note whether volume confirms the widening range.
Expansion cycles differ by asset class. Thai equities in thin holiday weeks can show ATR spikes on minimal volume. Cross-check with bid-ask width where your platform displays it, or with the prior week's average volume if not.