The post-spike base breakout, as a rule you can measure

The post-spike base breakout has three parts: a sharp run-up (the spike), a tight sideways range while volume dries up (the base), and a close back above the range on rising volume (the breakout). The prior spike proves demand; the base gives a clean risk level.

Defining it precisely

Vague: “it consolidated then broke out.” Precise: “≥40% run over N days, then a range whose width is ≤15% for ≥10 bars, then a close above the range high with volume > the base average.” Only the precise version can be back-tested.

Where the risk level lives

The base’s low is the natural stop: if price falls back into and through the base, the setup is wrong. That gives you a defined risk to size against — see position sizing — instead of a hope.

Read the measured base rate first

Before trading it, look at how this setup actually resolved across survivorship-free history (delisted names included). The honest numbers, not the textbook promise, tell you what to expect.