Calls and Puts

Every options trade resolves into one of four positions. Most traders learn one of them well and then graft the other three onto it later. That is why so much money gets lost to language confusion before any is lost to direction. The grammar of options is the first thing to get right.

On February 5, 2018 the VIX more than doubled in a single session, closing at 37.32 from a prior close of 17.31. The S&P 500 fell 4.1 percent. By the next morning Credit Suisse's inverse-VIX ETN, traded under the ticker XIV, had lost ninety-seven percent of its value and was being liquidated. The people holding XIV had bought it as a long position. The product itself was structurally short volatility. Most of the holders did not understand that the long thing they were holding had a short payoff inside it. They did not lose money on direction. They lost money on language. The grammar of positions matters in every market with optionality, and 0DTE is one of the markets where it matters most.

The buyer's side

A call is a contract. The holder has the right, not the obligation, to buy the underlying at a fixed price, the strike, at any moment up to and including expiration. The holder paid for that right in cash at the trade. If the underlying never trades above the strike, the right was worthless. The cash is gone and the contract expires. If the underlying trades above the strike, the right is worth at least the difference. On expiration day the math collapses to a clean settlement: the contract resolves into whatever intrinsic value is left.

A put is the mirror image. The holder has the right to sell the underlying at the strike. Worthless if the underlying never trades below the strike. Worth the difference, at minimum, if it does. Same cash-out-front structure, opposite direction.

The seller's side

Every contract somebody bought, somebody else sold. The seller, also called the writer, collected the premium at the trade. In exchange the seller is obligated to deliver. If the buyer of a call exercises, the seller hands over the underlying at the strike. If the buyer of a put exercises, the seller takes delivery at the strike. The seller's maximum profit is the premium received. The seller's loss can be much larger.

Asymmetry

The buyer pays a known cost for an unknown reward. The seller collects a known reward for an unknown cost.

What the premium pays for

Every option premium is the sum of two parts. Intrinsic value is how far in the money the contract already is. A call with strike 7200 when spot is 7220 carries twenty dollars of intrinsic value, every penny of it real, none of it a guess. Extrinsic value is the rest. It is the price of the time and the volatility still remaining, the optionality of all the things that could happen between now and expiration. On a long-dated option, extrinsic value is most of the premium. On a zero-DTE, extrinsic value is a candle that has been lit. It will be out by the close.

This is the central fact of expiration-day trading. Whatever a zero-DTE option finishes worth at the bell is purely intrinsic. The extrinsic component, however large it was at the open, decays to zero by 4 PM Eastern. Buyers of zero-DTE options are racing extrinsic value to zero. Sellers are betting it gets there before the buyers' direction does.

Long and short do not mean what you think

The language of options is borrowed from the language of stocks, and the borrowing is imperfect. In stock trading, long means I own it and want it to go up; short means I borrowed and sold it and want it to go down. In options those words refer only to whether you bought or sold the contract. They are accounting words, not directional ones.

1. ▸Long call: bought a call. Directional exposure is bullish. You want the underlying up.
2. ▸Long put: bought a put. Directional exposure is bearish. You want the underlying down.
3. ▸Short call: sold a call. Directional exposure is bearish or neutral. You profit when the underlying is flat or down.
4. ▸Short put: sold a put. Directional exposure is bullish or neutral. You profit when the underlying is flat or up.

Four positions. Two of them bullish, two of them bearish. The trap is that short call and long put are both bearish, but they are not the same trade. The long put has bounded risk (the premium paid) and large upside (the underlying can go to zero). The short call has bounded reward (the premium collected) and unbounded risk (the underlying has no ceiling). The grammar matters because the payoff diagrams are nothing alike.

Choosing the strike

The strike is the price the contract settles against. Every zero-DTE chain offers three categories of strike relative to spot at any moment, and the choice between them is a statement about the size of move the trader is willing to wait for.

• ▸In the money. Call strike below spot, put strike above spot. The contract already has intrinsic value. Premium is high. Delta is close to one. The position behaves nearly like leveraged exposure to the underlying.
• ▸At the money. Strike at or near spot. Gamma is highest in this band. Premium is sensitive to small moves. On any given zero-DTE chain, most volume clusters here.
• ▸Out of the money. Call strike above spot, put strike below spot. No intrinsic value yet. Cheap. The premium is entirely a bet on a move large enough to put the contract in the money before the close. Most likely to expire worthless. Lottery-shaped in payout if it does not.

A trader's choice of strike on a zero-DTE is a tactical statement about magnitude. At-the-money contracts pay off on modest moves and lose on stalls. Out-of-the-money contracts need a real push to print, and they print large when they do. In-the-money contracts move with the underlying, with the thicker premium acting as a buffer against being wrong. None of these are right or wrong in the abstract. They are right or wrong for the move the trader is expecting and the size they are willing to put behind it.