A geopolitical shock — a conflict, an attack, a crisis — that lands over a weekend or overnight can gap SPY hard at the next open, with no opportunity to react in between. These shock gaps are among the most dangerous events a trader faces precisely because the entire repricing happens in one jump.
Why shock gaps are different
Normal news gets priced continuously as it develops. A weekend geopolitical event doesn't — the market is closed, so all the fear and repositioning accumulate and release at once when futures reopen (Sunday evening ET) or at the cash open. The gap can be large and violent, often accompanied by a risk-off rotation (gold up, yields down) and an oil spike if energy supply is threatened. This is the extreme version of the weekend-news dynamic.
Why the first move is unreliable
The initial reaction to a geopolitical shock is often an emotional overreaction that partially reverses as cooler analysis sets in — markets have a long history of “buying the invasion” after an initial panic, once the actual economic impact is judged limited. But sometimes the shock is the start of something larger and the selling continues. You genuinely don't know in the first minutes, and the tape is at its thinnest and most volatile — the worst time to have conviction.
A weekend shock hands you a gap you couldn't trade into and a first move you can't trust. The only edge is patience — let the panic find its level before you act.
How to survive the reopen
Respect that you can't control gap risk — which is exactly why you size for the worst case and don't carry oversized positions into known weekend flashpoints. When the shock hits, avoid chasing the first violent move; let the map re-form and the initial panic exhaust (watch for the VIX spike fade dynamic) before committing. NoVo re-maps levels live as the market reprices, but the discipline to stand aside through the initial shock — and to never be over-sized into it — is what keeps a shock gap from becoming a disaster.