Basis & Basis Trades
The basis is the difference between a derivative's price (futures or perpetual swap) and the underlying spot price. In crypto, the most actively watched basis is between perpetual swaps and spot. Basis trades exploit this difference to capture yield while hedging out directional risk.
Basis = derivative price - spot price. When the perp trades above spot, the basis is positive (premium). When it trades below, the basis is negative (discount). The magnitude of the basis reflects the market's demand for leverage.
Calculating the Basis
The percentage basis is:
The basis and the funding rate are closely related. The funding rate is the mechanism that converges the basis toward zero over time. When basis is positive, positive funding (longs pay shorts) creates selling pressure on the perp, pushing it back toward spot. When basis is negative, negative funding (shorts pay longs) pulls the perp back up. In steady state, the annualized basis approximates the cumulative funding rate.
What Drives the Basis
The perpetual swap basis is driven by the balance of long and short demand:
Basis and Funding Rate
On perpetual swaps, the funding rate is the mechanism that keeps the perp price tethered to spot. When the basis is positive, funding is positive (longs pay shorts), which gradually pushes the perp price back down toward spot. When the basis is negative, funding is negative (shorts pay longs), pulling the perp price back up.
The funding rate is directly derived from the basis. A larger basis produces a larger funding rate, creating a stronger pull back toward spot.
Basis Is the Cost of Leverage
When the basis is high, longs are paying a steep price to stay long. That cost shows up as funding payments every funding period (typically every 8 hours). An annualized basis of 30% means leveraged longs are effectively paying 30% per year for the privilege of holding their position. This is the price the market charges for leverage demand.
Typical Basis by Asset
Different assets have structurally different basis profiles due to their supply and demand characteristics.
BTC
Tightest basis
- Typical annualized basis: 5-15% in bull markets
- Most liquid perp market, tightest spreads
- Basis compresses quickly after spikes
- Institutional arbitrage keeps basis in check
ETH
Moderate basis
- Typical annualized basis: 8-20% in bull markets
- Slightly wider than BTC due to higher beta
- Staking yield adds a floor to the basis
- Can decouple from BTC basis during ETH-specific events
Altcoins
Widest basis
- Typical annualized basis: 15-50%+ in bull markets
- Less liquid, wider spreads, more volatile
- Basis can stay elevated for weeks during hype cycles
- Higher risk of liquidation cascades narrowing basis rapidly
Basis During Market Events
Reading Basis as a Market Signal
Even if you never trade basis directly, the basis level tells you something useful about market conditions:
| Basis Level | What It Signals |
|---|---|
| High positive (>15% ann.) | Aggressive long demand. Traders are willing to pay a steep cost for leverage. Often seen near local tops. |
| Moderate positive (5-15% ann.) | Healthy bullish bias. Sustainable leverage demand. |
| Near zero | Equilibrium. No strong conviction in either direction. |
| Negative | Fear or hedging. Shorts are dominant. Can signal capitulation near bottoms. |
Basis Is Forward-Looking Sentiment
Unlike price, which shows you what happened, basis shows you what traders are willing to pay right now for future exposure. A rising basis during flat price action means conviction is building. A collapsing basis during a rally means leveraged longs are exiting or getting liquidated.
Basis vs. Funding Rate
People sometimes use "basis" and "funding rate" interchangeably, but they are different:
Basis
The price difference
- Measured in dollars or percentage
- Snapshot of perp price minus spot price at a given moment
- Can be annualized for comparison across time periods
- Changes continuously with market prices
Funding Rate
The payment mechanism
- Measured in percentage per period (e.g., 0.01% per 8h)
- Derived from the basis but includes dampening and clamp logic
- Paid/received at fixed intervals (1h, 4h, or 8h depending on exchange)
- Used to anchor the perp price back toward spot
The basis drives the funding rate, but the relationship is not linear. Most exchanges apply a clamp to prevent extreme funding rates and add an interest rate component. The result is that funding rate converges toward basis over time but does not match it exactly in any single period.
💡 Tip: Try answering each question yourself before revealing the answer.
Fungibility and Convergence
The basis must converge to zero at expiry. This is the fundamental guarantee that makes basis trading possible: a future and its underlying are the same asset at expiry, so their prices must be equal at that moment. For perpetual swaps, there is no single expiry, but the funding rate mechanism creates continuous convergence pressure.
Why Convergence Must Happen
At expiry, a futures contract settles against the spot price (or an index derived from it). If the future were trading above spot at settlement, you could buy spot, sell the future, and deliver for a risk-free profit. If below spot, the reverse. Arbitrageurs enforce this identity.
For perps, the mechanism is indirect: funding payments make it costly to maintain positions that push the perp away from spot. Positive basis means longs pay shorts, which incentivizes selling the perp. Negative basis means shorts pay longs, incentivizing buying. The funding rate is the engine of convergence.
When Convergence Fails
Convergence can temporarily fail under extreme conditions:
- Exchange insolvency: If the exchange cannot honor settlement (as with FTX), the future and spot diverge permanently. The "arbitrage" was never riskless because it relied on the exchange as counterparty.
- Settlement manipulation: If the settlement index can be manipulated, the future converges to a distorted price. This is why exchanges use multi-source indices with outlier filtering.
- Delivery failures: In traditional commodity markets, physical delivery failures break convergence. In crypto, cash settlement eliminates this risk but introduces index manipulation risk instead.
- Circuit breakers and halts: If trading is halted on one venue but not another, the two legs of a basis trade can diverge without recourse until trading resumes.
Convergence Is a Counterparty Bet
Every basis trade that relies on convergence is implicitly a bet on the solvency and integrity of the settlement mechanism. The basis itself may be "free money," but the convergence that delivers it depends on infrastructure that is not guaranteed. FTX basis trades were profitable right up until they were worthless.
Option Arbitrage via Basis
Options traders use the basis to find mispricings through put-call parity. The connection is the forward price.
Put-call parity states:
But in crypto, the relevant "S" is often not the spot price -- it is the forward price implied by the futures or perp market. If the basis is large, the forward differs materially from spot, and options priced off spot will appear mispriced relative to options priced off the forward.
The arbitrage: if options are priced using spot while the actual forward (spot + basis) is higher, calls will be cheap and puts will be expensive relative to the forward-based fair value. A trader can:
- Buy the "cheap" calls
- Sell the "expensive" puts
- Short the forward (via futures or perp)
This locks in the parity difference using the correct forward price. The profit comes from the market's inconsistent treatment of the basis across options and futures.
Calendar Spread Arbitrage
For assets with listed futures at multiple expiries, the term structure of futures prices should reflect the cost of carry between expiries. When it doesn't, calendar spread arbitrage opportunities arise.
The Normal Term Structure
In a normal market, far-dated futures trade at a premium to near-dated futures, reflecting the time value of money and the cost of holding the position:
When the actual spread between expiries deviates from this theoretical value, the difference can be captured.
Exploiting Term Structure Kinks
A "kink" in the term structure is an abnormal spread between two adjacent expiries. These occur when:
- Supply/demand imbalance at a specific expiry: A large hedger rolls their position from one expiry to another, temporarily distorting the spread.
- Event-driven repricing: A major event (halving, ETF decision, regulatory ruling) falls between two expiries. The near-dated future may not reflect the event, while the far-dated one does, creating an abnormal spread.
- Liquidity differences: Illiquid far-dated contracts can be mispriced simply because not enough participants are trading them to enforce fair value.
The trade: buy the relatively cheap expiry, sell the relatively expensive one. Wait for the spread to normalize. The profit is the convergence of the spread toward its theoretical value, regardless of where the underlying goes.
Risk in Calendar Spreads
Calendar spreads are lower risk than directional futures because the two legs offset most price movement. However, they are not risk-free:
- Margin on both legs: You post margin on two futures contracts, tying up capital.
- The spread can widen before it narrows: If the distortion was driven by a fundamental factor you didn't account for, the "cheap" leg may stay cheap.
- Roll risk: If you need to close one leg before the other, you have temporary directional exposure.
- Funding rate changes: For perp-based calendar spreads, changes in funding rates alter the expected carry and can turn a favorable spread into an unfavorable one.
Related:
- Perp Funding - How the funding rate mechanism works
- Beta & Alpha - Measuring exposure and excess returns
- Auto-Deleveraging - ADL risk in basis trades
- Options vs. Perpetuals - Structural differences between the two instruments
- Fear & Greed Indices - Sentiment indicators
- Put-Call Parity - The parity relationship and its connection to the forward
- Term Structure - Volatility term structure and its parallels to futures term structure