The strike price is the fixed price at which an option lets you buy (for a call) or sell (for a put) the underlying. It's the single most defining number on an option — it sets the reference point everything else is measured against.

How the strike works

A call with a $500 strike gives you the right to buy SPY at $500; a put with a $500 strike gives you the right to sell at $500. If SPY is above the call's strike (or below the put's), the option has real (“intrinsic”) value — it's in the money. If not, its value is all time and probability — out of the money. The strike is the line that divides those two states.

Why the strike choice matters

Which strike you pick shapes the trade entirely: strikes near the current price (higher delta) move closely with SPY and cost more; strikes far away (low delta) are cheap but need a big move to pay off (too far OTM is a common beginner trap). For scalping, strike selection is a real decision — one NoVo handles automatically when you execute.

The strike is the price your option is built around. Everything about what it's worth — and how it moves — starts from that one number.

The quick takeaway

The strike price defines what price your option is tied to. Combined with whether it's a call or put and the expiration, it fully specifies the contract. Understanding the strike is step one to reading an options quote and picking a trade — and it's the foundation for everything else in options.