Great Chart: Cable vs. 2Y UK – US IR Differential

As for EURUSD and the 10Y interest rate (IR) spread (here) or for USDJPY versus the equity market (TOPIX, see here), the same interesting divergence has been occurring between Cable and the 2Y IR differential. We mentioned in many of our posts that the interest rate differential (either short term 2Y or long term 10Y) has been considered as one of the main drivers of a currency pair for a long time. For instance, in our BEER FX Model, we used the terms-of-trades, inflation and the 10-year interest rates differentials for our cross-sectional study, using the US Dollar as the base country and currency (see post here).

Hence, if you look back over the past few years, there is a significant co-movement between the two times series. As you know, the ST 2Y IR differential reflects the expected announcements from either UK or US policymakers concerning the future path of the target IR set by the central bank. For instance, between summer 2013 (when Governor Carney took office at the BoE) and summer 2014, the 2Y IR differential went up from 0 to 45bps on the back of strong UK fundamentals (fastest growing economy in G7 in 2014) and market participants starting to price in a rate hike as early as Q4 2014 or Q1 2015 according to the short-sterling futures contract (see July 2014 update). The increase of both the 2Y IR differential and the short-sterling futures implied rate brought Cable to its highest level since October 2008 at 1.72 in July 2014. However, both trends reversed that summer with the US Dollar waking up from its LT coma and the UK starting to show some weaknesses in its fundamentals. At that time, we entered a 2Y+ Cable bear market, and if we omit the pound ‘flash crash’ in early October 2016 and set the low at 1.20, Cable experienced a 30-percent depreciation. Therefore, this fall moved the British pound from being a slightly overvalued currency to a clearly undervalued currency if we look at some broad measures such as the real effective exchange rate (REER). According to the REER, the Pound is 15% far away from its 23Y LT average (GBP REER).

If we look at the last quarter of 2017, despite a 50bps drop in the 2Y differential (currently trading at -1.44%), Cable found support slightly below its 100D SMA each time and the pair has shown strong momentum since the beginning of the year. We believe that the strong decrease in the IR differential lately comes from an (over) confident market pricing in three Fed hikes next year (probability of 4 or more rate hikes stands at 9% in 2018). However, we think that this current excitement may slow down in Q1 2018, hence readjust the IR differentials, which is going to be positive for the British pound against the greenback. In our view, the 1.40 level seems reasonable for Cable in the medium term (1-3M), which corresponds to the 38.2% Fibonacci retracement of the 1.20 – 1.72 range.

Chart: GBPUSD vs. 2Y IR differential (blue line, rhs) Source: Reuters Eikon


One thought on “Great Chart: Cable vs. 2Y UK – US IR Differential

Leave a Reply