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Inferring Meeting-Date Rate Expectations from STIR Futures and OIS

Article Quant Q&A · Author: user3741124

Summary

Short-term interest rate futures imply an average reference rate over each contract period. To estimate the rate expected after a central bank meeting, carry the known pre-meeting rate across the days before the meeting, then solve a day-weighted average using the contract’s implied rate. The example applies this method to Federal Funds futures and finds an estimate close to the cited market display.

The calculation depends on assumptions and market conventions. The result can vary with the price source, settlement basis, timing of the snapshot, or adjustments for the gap between the effective rate and the central bank’s target range. OIS rates offer another route: equate the fixed leg with the compounded expected daily floating rates and solve for the unknown period rates. The document mentions ASX 30-day cash rate futures for Australian and New Zealand expectations, while noting that other markets may rely on OIS. The method estimates market-implied rates; it does not establish the actual future policy path or explain how to trade it.

Key ideas

  • A STIR futures quote reflects an average reference rate over its contract period.
  • A meeting-month implied rate can be isolated by weighting the known pre-meeting rate and solving for the remaining days.
  • The estimate depends on contract conventions, price source, and the market snapshot used.
  • OIS quotes can also be used to infer expected overnight rates through daily compounding.
  • Market-implied policy expectations are estimates rather than guaranteed outcomes.

Tags

Full text
# how to calculate the implied interest rates using STIRs futures?


# how to calculate the implied interest rates using STIRs futures?












I saw a post of trader sharing his expectations of implied interest rates on different meetings dates of different Central banks using STIRs ScreenShot and am trying to figure out how he did it ? my second question is what are the STIR futures of RBA,RBNZ,BOC,BOJ,SNB

## Answer by AKdemy (score 4, accepted)

https://quant.stackexchange.com/a/71805

Unlike @Chris Edmonton, I am not sure what the screenshot shows, because in my opinion it does not show if Futures or OIS is used.

In any case, the idea is the same:

- Under the assumption that only central bank actions will impact the effective interest rate of an economy, you can push the expected overnight rates forward and backward through the tenor structure.

- With futures, you get the chain (all tenors) and look at the individual dates. Some contract months will not span central bank meetings, others will. Therefore, you have the future representing the average rate over the period, where it could be higher/lower prior to the meeting date, lower/higher after the meeting date. You can carry the rate forward where there is no meeting - meaning you know the rate prior to the meeting date - and solve the equation $$days_{total}*Future_{meeting_{month}} = days_{prior_{meeting}}*Future_{prior_m} + days_{after}*r_{implied}$$

To provide a specific example, let's look at the FED Funds futures on Bloomberg. In case you have access to BBG, you can look at {WIRP} and {FFA Comdty CT} for the following screens:

Computing the above logic with the market data results in the following lines of

```
days_total = 31
days_prior = 2
days_after = days_total - days_prior
future_meeting_month = 3.13
future_prior_month = 3.225

r_implied_may = (future_meeting_month*days_total - future_prior_month*days_prior)/days_after
```

It is reasonably close to the value Bloomberg shows (3.12) for this meeting date. Maybe they use a slightly different logic but the general idea holds (e.g. settlement prices vs Last traded price vs a snapshot of prices at some given time or they adjust for the "basis" between the current rate and the mid between the upper and lower bound or the like).

The CME offers a tool similar to WIRP on BBG - the so called CME FED Watch tool, which provides the probabilities just like WIRP (that's something frequently looked at and discussed in the market, as @KevinT mentioned).

For RBA, you can use the ASX 30 Day Interbank Cash Rate Futures . Bloomberg only displays OIS for the others. Though, I think @KevinT suggestions are sound.

Apart from futures, you can also look at OIS swaps, which for some countries even have directly quoted central bank meeting date swaps. If not, you can still rely on the following equilibrium: $$ 1 + \frac{r*n}{360} = \prod_{i=1}^n \left(1+ \frac{r_i*d_i}{360}\right)$$ where the left hand side is the fixed part (r is the quoted OIS price / fixed rate), and the RHS the floating part, with $r_i$ denoting the expected floating rate on the $i^{th}$ day, $d_i$ the number of days $r_i$ applies for (1 for weekdays, 3 for weekends) and n is the total number of days for the swap. Since r, n and $d_i$ is known, you can solve this.

## Answer by KevinT (score 4)

https://quant.stackexchange.com/a/71801

Answering a bit broader / more general: usually, traders deduce the expectations about central bank hikes or cuts from the market quotes of liquidly traded interest rate derivatives. The same holds for the overnight based interest rates -- and in this case, the usual suspects are STIR Futures and Overnight Indexed Swaps (OIS). You specifically asked about the former, so as an arbitrary / meaningless example, let's just say that a 3 month future with September expiry is quoted at 99.0, meaning a 1% (compound or average) interest rate for the reference period (June - September). If your current fixing is at 0.75%, it means the market implies a hike of 25bps for the central bank meeting that falls within this period. (Often traders also express the hikes in terms of "probabilities" of 25bps hikes --> here you'd have a 100% chance / agreement of a 25bps hike).

Lastly, regarding RFR based futures in the markets you asked:

- AUD & NZD: you have 30 Day Interbank Cash Rate Futures that are based on the average RBA Overnight Cash Rate (RBNZ cash rate, respectively). Apparently both can be traded on ASX (see here and here). What might interest you particularly is that the ASX actually developed a webpage called RBA Rate Indicator; it tracks exactly those expectations I mentioned above - see here.







HTH

## Answer by Chris Edmonton (score 0)

https://quant.stackexchange.com/a/71793

To answer your first question, there are markets for forward overnight interest rate swaps (OIS) starting and ending on consecutive central bank rate decision dates. Your screenshot shows quotes for these swaps.

Shown in full with attribution under the source's licence. Licence: CC BY-SA 4.0 (Stack Exchange)

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.