The GEX Battle Terminal is an advanced interactive simulation designed to visualize the invisible mechanics that drive modern stock market volatility: Dealer Gamma Exposure (GEX).
Market Makers (e.g., Citadel Securities, Virtu) provide liquidity. Their goal is not to bet on the direction of the market. Their goal is to stay Delta Neutral (zero risk).
This simulator models the mathematical relationship between Options and the Underlying Stock.
To understand this, imagine the Dealer is like a Bookie taking bets.
You buy Puts. The Dealer is Short Puts. To hedge, the Dealer SELLS Stock (shorts it). This selling pressure pushes prices down, forcing them to sell even more.
What if the Dealer DOESN'T want the price to go up?
Sometimes, when the market stretches too far past the "Gamma Wall" (e.g., Strike 4000), the Dealer starts selling into strength to act as a rubber band.
Q: "Is the S&P 500 (SPX) index value automatically based on underlying stocks, or do Market Makers move it directly?"
A: It is BOTH. This is known as "The Tail Wagging the Dog."
You might ask: "If the Dealer constantly has to buy high and sell low to hedge, don't they lose money?"
This is the most critical concept in market microstructure. Dealers are Volatility Arbitrageurs.
Dealers never transact at the "Fair Price." They bid $99.90 and ask $100.10. Every trade captures this spread, paying for their hedging costs.
When Dealers sell you an option, they are Short Gamma (Risk) but Long Theta (Profit). Every day the market doesn't crash, the option loses value, and the Dealer keeps that value.
They hedge the Net Risk of thousands of trades. Your Long Call might be cancelled out by someone else's Long Put. They only hedge what's left.
They lose when the market moves faster than they can hedge (Flash Crash). This is known as Negative Convexity.
| Action | What You Are Doing | Your View | Dealer Reaction |
|---|---|---|---|
| Buy Stock | Buying shares of the company. | "Price will go UP." | None. |
| Short Stock | Borrowing shares to sell them. | "Price will go DOWN." | None. |
| Long Call | Buying the Right to buy stock later. | "Price will MOON." | Dealer Hedges: BUY STOCK. |
| Long Put | Buying the Right to sell stock later. | "Price will CRASH." | Dealer Hedges: SELL STOCK. |
| Short Call | Selling the Obligation (Casino). | "Price won't go up." | Dealer Hedges: SELL STOCK. |
| Short Put | Selling the Obligation (Casino). | "Price won't go down." | Dealer Hedges: BUY STOCK. |
A reference of what you own and who is accountable.
| Instrument | Tradeable? | What is it? | Accountable |
|---|---|---|---|
| Index (SPX) | ❌ NO | Mathematical average. A "Thermometer". | S&P Dow Jones (The Calculator) |
| Calculated Volatility (VIX) | ❌ NO | Math calculation of implied volatility. | CBOE (The Math) |
| Instrument | Tradeable? | What is it? | Accountable |
|---|---|---|---|
| Stocks (AAPL) | ✅ YES | Partial ownership of a company. | The Company / SEC |
| ETF (SPY) | ✅ YES | A "Basket" fund holding the actual stocks. | Fund Manager (State Street) |
| Bonds | ✅ YES | A loan to the government collecting interest. | The US Treasury |
| Crypto (BTC) | ✅ YES | Digital bearer asset on a decentralized ledger. | The Code / Protocol |
| Instrument | Tradeable? | What is it? | Accountable |
|---|---|---|---|
| Futures (ES) | ✅ YES | Contract to buy/sell index later. Highly leveraged. | CME Exchange (Holds Margin) |
| Options | ✅ YES | Right (Buyer) vs Obligation (Seller) to trade. | OCC (Guarantees Contract) |