Three questions: is the leading index above its 50-day moving average? Is that 50-day average itself rising or falling? And is the volatility index calm or spiking? Index above a rising average with calm volatility — an environment where breakouts work. Index below a falling average with volatility spiking — an environment where nearly every breakout fails.

A fourth question that adds a lot: market breadth. If the index is rising but only five mega-caps are pulling it, the advance is fragile. If most stocks participate, the base is broad and breakouts are supported.

In an uptrend: full-size positions, breakouts and pullbacks with the trend, maximum position count. In a chop: half size, fewer positions, prefer buying the bottom of a range and selling the top. In a downtrend: minimum size or none. A swing trader sitting out three weeks of a downtrend isn't "missing out" — they're protecting capital for the next environment.

When a regime flips, it flips fast. The early tell is usually not the index but behaviour: breakouts starting to fail one after another, and leading stocks breaking down on heavy volume. If three good setups in a row failed for no reason — that's the market talking, not luck.