Futures Basis PnL
PDF Version1. Introduction
Basis trading is an important trading activity in the futures markets for hedging and speculative proprietary trading. It is therefore important to understand its basics.
Basis is defined as the difference between the spot price(a.k.a. cash price) and futures price. We will consider a single time period with two points T1 and T2 for the following discussion. T1 is the time we open a position (long or short) and T2 is the when that position is closed.
2. Long and Short
Let’s consider an asset whose price is A1 at T1 and A2 at T2. Going long means buying the asset at T1 and selling it at T2. Going short, on the other hand, is selling it at T1 and buying it back at T2. Let’s also assume that we just trade one unit of the asset and there is no transaction costs (broker fees, bid/ask spreads, etc.) for the sake emphasizing main ideas.
Profit/loss (PnL for short) profile of going long and short are then:
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Long PnL = A2 - A1
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Short PnL = A1 - A2
Most of the assets we encounter have positive prices. However, there are some synthetic assets such as spreads which are linear combinations of other assets and therefore can have both positive as well as negative prices. This might have some unexpected implications in terms of PnL calculation as discussed below
3. Generalized PnL for Long/Short Positions
PnL for a long position is positive if the prices are increasing whether those prices are negative or positive. Similarly, PnL for a short position is positive if the prices are decreasing irrespective of whether they are positive or negative. In other words, prices are considered in an algebraic sense in PnL calculations. Market with increasing prices are referred as "bull" markets and those with decreasing prices are referred as "bear" markets, so we will use those terms as well in the discussions that will follow.
Given two prices A1 and A2 corresponding to the asset price at T1 and T2 respectively, there are 4 different cases to consider:
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Negative Increasing Prices: A1 < A2 < 0
Long PnL = A2 - A1 > 0 (i.e. positive/profit)
Short PnL = A1 - A2 < 0 (i.e. negative/loss) -
Positive Increasing Prices: 0 < A1 < A2
Long PnL = A2 - A1 > 0 (i.e. positive/profit)
Short PnL = A1 - A2 < 0 (i.e. negative/loss) -
Negative Decreasing Prices: A2 < A1 < 0
Long PnL = A2 - A1 < 0 (i.e. negative/loss)
Short PnL = A1 - A2 > 0 (i.e. positive/profit) -
Positive Decreasing Prices: 0 < A2 < A1
Long PnL = A2 - A1 < 0 (i.e. negative/loss)
Short PnL = A1 - A2 > 0 (i.e. positive/profit)
A geometric representation of the above formulas with some illustrative concerete values can be seen in Long/Short PnL Diagram.
4. Basis Position
In futures trading basis is defined as the difference between spot(cash) price and futures price. Let’s again consider a single period with the beginning and end points of T1 and T2 respectively. We will designate the cash price, future price and basis with letters C, F and B respectively. Their values at the beginning and end of the period is referred with relevant subscripts as in that C1 is the cash price at T1 and C2 is the cash price at T2.
Basis is then defined as follows:
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At T1 : B1 = C1 - F1
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At T2 : B2 = C2 - F2
Basis can be positive or negative depending on whether cash/spot prices are higher or lower than the futures prices. A market where futures prices are higher than spot/cash prices is said to be in "contango". Basis, by definition, will be negative in a contango market. A market where futures prices are lower than spot/cash prices is said to be in "backwardation". Basis in such market will be positive.
Markets are normally expected to be in contango (negative basis) as prices generally increase with time (think of inflation). However, short and long term supply/demand dynamics can easily change this and turn a market into backwardation. For example, if there is currently some supply shortages in the market due to some temporary conditions (i.e. they will disappear in next several months), spot prices will be higher than usual due to supply shortages. Futures prices however might stay normal if the market perceives this to be a transionary situation. This will make the spot prices being higher than the futures prices put the market into backwardation.
As basis can be positive as well as negative, terms of "expanding" and "narrowing" are used by basis traders to refer to the absolute value(size) of the basis irrespective of the mathematical sign of the basis. So, when basis changes from -0.50 to -0.25 it is said to be narrowing(contracting) as it’s size(absolute value) has decreased from 0.50 to 0.25. Similary, when it changes from -0.25 to -0.50 it is said to have expanded.
Using the above basis definition, we can calculate PnL for long and short basis positions:
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Long Basis(LB): LB PnL = B2 - B1
= (C2 - F2) - (C1 - F1)
= (C2 - C1) + (F1 - F2)
This is just Long Cash(LC), Short Futures (SF):
LB = LC + SF -
Short Basis(SB): SB PnL = B1 - B2
= (C1 - F1) - (C2 - F2)
= (C1 - C2) + (F2 - F1)
This is just Short Cash(SC), Long Futures (LF).
SB = SC + LF
If the primary purpose of our trading activity is hedging, long basis position can be referred as "short hedger" as we will be hedging cash position with short futures position. Short basis position is called "long hedger" for a similar reason.
5. Basis PnL Profile
How will the PnL of basis positions will change over a single period in different market conditions? More specifically we will consider rising(bull)/declining(bear) markets, contango/backwardation, long/short position, expanding/narrowing basis. This is equivalent to 2x2x2x2 = 16 different cases
PnL for short positions are the opposite of the that of long one as seen the previous discussion. Therefore we will focus on the long basis positions and infer the results for the short position as the opposite of the long ones e.g. if long PnL is positive/profit, short one will be negative/loss.
Recall that PnL for long basis position is B2 - B1 and basis values can be both positive and negative. As discussed in Generalized PnL for Long/Short Positions, there are two cases where long position PnL can be positive for an asset with both positive and negative prices (as is the case for the basis). Positive prices mean spot/cash prices being higher than futures and therefore backwardation; negative prices mean the opposite i.e. contango.
In Long/Short PnL Diagram we used the terms "incrasing" and "decreasing" to describe the prices. These terms were used in their mathematical sense. A more market practioner-oriented description would relate the meaning of those terms to the contango (negative prices) and backwardation (positive prices) markets. In contanto markets(negative basis), long position PnL is positive when the basis is contracting/narrowing (i.e. its absolute value decreasing). This can be seen in the top left corner of Long/Short PnL Diagram. In backwardation markets (positive basis), In contanto markets(negative basis), long position PnL is positive when the basis is widenign/expanding (i.e. its absolute value increasing). This can be seen in the top right corner of Long/Short PnL Diagram.
Basis Position Market Direction Neutrality
A given basis position PnL does not specifically depend the market direction (whether it is increasing/bull or decreasing/bear). In other words, basis trading is market direction neutral. It primarily depends on the mathematical increase or decrease of the basis. This then translates to:
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To see the validity of the above assertion first notice the following:
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Long basis PnL only depends on the mathematical change in the basis (i.e. B2 - B1 )
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Same mathematical basis changes could take place both in rising/bull and falling/bear markets.
Second point above can best be illustrated geometrically through some hypotetical market scenario diagrams.
5.1. Bull Market Basis Scenarios for Long Basis Position
Consider the bull market scenarios as illustrated in the following diagram:
We will consider each cases in that diagram separately and analyze the PnL of a long basis position. Recall that long basis position is equivalent to a combination of long cash and short futures positions as described in "Long Basis PnL Formula". Short basis position PnL will immediately follow as the opposite of the long basis PnL, so we won’t explicity state it here.
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Widening Basis in Contango Market: This is illustrated in the bottom left corner of the diagram. While we make positive PnL from the long cash position, we lose money from short futures position. The loss from the short futures position is higher than the profit from long cash position, resulting in a net negative PnL. To see it notice the following:
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Futures prices start and stay higher than the spot prices (Contango market)
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The gap between the futures price and the spot price widens at the end of priod, implying that the future price has increased more than the spot price.
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Narrowing Basis in Contango Market: This is illustrated in the top left corner of the diagram. While we make positive PnL from the long cash position, we lose money from short futures position. The loss from short futures position is lower than the profit from long cash position, resulting in an overall positive PnL. To see it notice the following:
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Futures prices start and stay higher than the spot prices (Contango market)
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The gap between the future price and spot price narrows at the end of priod, implying that the spot price has increased more than the futures price.
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Widening Basis in Backwardation Market: This is illustrated in the bottom right corner of the diagram. While we make positive PnL from the long cash position, we lose money from the short futures position. The loss from short futures position is lower than the profit from long cash position, resulting in an overall positive PnL. To see it notice the following:
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Spot price starts and stays above than the futures price (backwardation market)
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The gap between the spot price and futures price widens at the end of priod, implying that the spot price has increased more than the futures price.
-
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Narrowing Basis in Backwardation Market: This is illustrated in the top left corner of the diagram. While we make positive PnL from the long cash position, we lose money from the short futures position. The loss from short futures position is higher than the profit from long cash position, resulting in an overall negative PnL. To see it notice the following:
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Spot price starts and stays above than the futures price (backwardation market)
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The gap between the spot price and futures price narrows at the end of priod, implying that the futures price has increased more than the spot price.
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5.2. Bear Market Basis Scenarios for Long Basis Position
Consider the bear market scenarios as illustrated in the following diagram:
As in Bear Market Basis Scenarios for Long Basis Position, we will consider four different scenarios for a long basis position. Short basis position PnL will be the numerical opposite of the respective long position PnL and will be not stated explicitly.
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Widening Basis in Contango Market: This is illustrated in the bottom left of the diagram. While we make positive PnL from short futures position, we lose money from long cash position. The profit from short futures position is lower than the loss from long cash position becasue the futures price drops less than the spot price. To see this, notice the following:
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The futures price starts and stays above the spot price (contango market)
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The gap between the futures price and the spot price widens at the end of priod, implying that the spot price has dropped more than the futures price.
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Narrowing Basis in Contango Market: This is illustrated in the top left of the diagram. While we make positive PnL from short futures position, we lose money from long cash position. The profit from short futures position is higher than the loss from long cash position becasue the futures price drops more than the spot price. To see this, notice the following:
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The futures price starts and stays above the spot price (contango market)
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The gap between the futures price and the spot price narrows at the end of priod, implying that the futures price has dropped more than the spot price.
-
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Widening Basis in Backwardation Market: This is illustrated in the bottom right of the diagram. While we make positive PnL from short futures position, we lose money from long cash position. The profit from short futures position is higher than the loss from long cash position becasue the futures price drops more than the spot price. To see this, notice the following:
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The spot price starts and stays above the futures price (backwardation market)
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The gap between the futures price and the spot price widens at the end of priod, implying that the spot price has dropped less than the futures price.
-
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Narrowing Basis in Backwardation Market: This is illustrated in the top right of the diagram. While we make positive PnL from short futures position, we lose money from long cash position. The profit from short futures position is lower than the loss from long cash position becasue the futures price drops less than the spot price. To see this, notice the following:
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The spot price starts and stays above the futures price (backwardation market)
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The gap between the futures price and the spot price narrows at the end of priod, implying that the spot price has dropped more than the futures price.
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6. Conclusion
We have established the following in this paper:
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Long basis position is equivalent to a combination of long cash and short futures positions
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Short basis PnL is just numerical opposite of the long basis positions i.e. a combination of short cash and long futures positions
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Long basis PnL depends on the market (whether it is in contango or backwardation) and the dynamics of the basis (whether it is narrowing or widening). It does not, however, depends on whether it is a bull/rising or bear market!
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Long basis position PnL is positive when either the increase in the spot price is higher than the increase in the futures price or the decrease in the spot price is lower than the decrease int the futures prices. The former happens when the basis narrows in a contango market and the latter happens when the basis widends in a backwardation market.
We now summarize the PnL implication of 16 cases mentioned earlier in the paper in the following table:
Position | Mkt Dir. | Market | Basis | PnL |
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Long |
Bull |
Contango |
Widening |
Negative |
Long |
Bear |
Contango |
Widening |
Negative |
Long |
Bull |
Contango |
Narrowing |
Positive |
Long |
Bear |
Contango |
Narrowing |
Positive |
Long |
Bull |
Backwardation |
Widening |
Positive |
Long |
Bear |
Backwardation |
Widening |
Positive |
Long |
Bull |
Backwardation |
Narrowing |
Negative |
Long |
Bear |
Backwardation |
Narrowing |
Negative |
Short |
Bull |
Contango |
Widening |
Positive |
Short |
Bear |
Contango |
Widening |
Positive |
Short |
Bull |
Contango |
Narrowing |
Negative |
Short |
Bear |
Contango |
Narrowing |
Negative |
Short |
Bull |
Backwardation |
Widening |
Negative |
Short |
Bear |
Backwardation |
Widening |
Negative |
Short |
Bull |
Backwardation |
Narrowing |
Positive |
Short |
Bear |
Backwardation |
Narrowing |
Positive |