The dollar index printed 101.424 in the London morning, its highest since 29 July, taking out the 24 September high of 101.398 by twenty-six thousandths of a point. Over the same hours dollar-yen has traded a fifty-two pip range for the entire day — Tokyo and London combined, roughly thirteen hours — against a one-week implied volatility of 10.50 per cent that prices about a hundred and four pips of one-sigma daily movement. Exactly half. The dollar is trending and your yen pair is not, and those two facts are not in tension: the trend is being expressed almost entirely through the euro and sterling legs while the yen leg sits still. If you size dollar-yen off a dollar-index breakout today you are buying a move that is happening somewhere else.
Fifty-two pips against a hundred and four
Minkabu’s currency-option page gave dollar-yen one-week implied at 10.50 per cent yesterday morning. On a 252-day year that is 0.66 per cent of daily movement at one standard deviation, or 104 pips at 157.35. Here is what the day has actually delivered: Tokyo traded 157.21 to 157.58, a 37-pip range. London extended the high to 157.72 at 10:15 UTC and then extended the low to 157.20 at 11:20, and at the time of writing spot is 157.25. High to low for the whole session so far is 52 pips.
Fifty-two is 50.0 per cent of the one-sigma figure with two of the three sessions finished. The US session would have to deliver another fifty-two pips of genuinely new range — not retracement inside what has already traded, new highs or new lows — simply to make the day average. That is possible; 14:00 UTC carries two US releases in the same minute and a 4.9-billion-euro option cut. But the burden of proof has shifted, and it has shifted against the option price.
This is the second half of a comparison this desk started yesterday morning and could only half-make. Then the question was whether Tokyo’s 37 pips — 35.6 per cent of a sigma — was an Asia-hours artefact that London would correct. It was not corrected. It was extended.
London added fifteen pips of range and gave the high straight back
The precise accounting matters here, because “London traded 157.20 to 157.72” overstates what London did. Tokyo had already established 157.21 and 157.58. London’s contribution to the day’s range is fourteen pips of new high and one pip of new low: fifteen pips of price the Asian session had not already visited, in the busiest six hours of the FX day.
And it did not hold any of it. The pair came off 157.72 to 157.20 in about an hour, and is now at 157.25, ten pips below where Tokyo closed it at 157.35. So the day’s shape is a fifty-two pip round trip with the close-to-date roughly where it started. Against Gaitame’s published forecast band of 156.50 to 158.20, spot sits 95 pips below the ceiling and 75 above the floor, having used 30.6 per cent of a 170-pip band. Two consecutive sessions have now finished near the middle of that band without touching either edge.
What that is worth to you is a gamma statement, not a directional one. If you are long options on this pair you have paid for 104 pips a day and been given 52. If you are running a breakout system with a fixed pip trigger, it has had two clean chances to fire today and both were fourteen-pip extensions that reversed. If you are running mean reversion, it has been a good day and the option market disagrees with you about tomorrow.
The trend is in the euro leg
Here is the same period in the other pairs. EUR/USD fell from a Tokyo high of 1.1374 to 1.1333 in London, forty-one pips, and 1.1333 is a three-month low — eight pips above the 24 June low of 1.1325. GBP/USD went from 1.3260 to 1.3221, thirty-nine pips. Dollar-yen went ten pips the other way, net, on the day.
So the dollar index at a two-month high is being built by the euro and sterling legs moving forty pips each while the yen leg contributes nothing. That is not a puzzle if you remember what is sitting under dollar-yen: a Ministry of Finance that has verbally intervened twice in four sessions, a 157 to 158 zone that the Japanese commentary describes as heavy, and a 160 level that everyone agrees is defended. Yen-selling has an asymmetric tail risk attached to it that euro-selling does not. The index is the average of legs with very different risk profiles, and today the constrained leg is the one most retail dollar exposure is in.
The practical version: a correlated-exposure check that treats a long-dollar view as one position sized across dollar-yen, euro-dollar and cable is mispricing itself today. The three legs are not delivering the same move and they do not carry the same tail.
The strike grew 8.9 per cent, and price walked away from it. Twice.
Yesterday a 4.5-billion-euro EUR/USD strike at 1.1400 expired at the 14:00 cut having never traded — the session high was five pips short. This morning the same strike came back for today’s cut at 4.9 billion euros, 8.9 per cent larger, with spot at 1.1357 and forty-three pips below it. This desk published a rule rather than a prediction: arm a filter around the 14:00 cut only if spot comes inside roughly fifteen pips of 1.1400 before 13:30 UTC, and otherwise leave the window out of the schedule entirely.
The closest EUR/USD has come to 1.1400 at any point today is 1.1374, in the Tokyo morning: twenty-six pips. It has since gone forty-one pips the other way to a three-month low. With roughly two hours to the cutoff the condition is not met, and it would take a sixty-seven pip rally to meet it. We will not declare the test formally settled until 13:30 has passed, but there is no honest reading of this tape in which the filter should be armed.
Two nulls in two days on the identical strike, with the notional growing between them, is worth more than one. The lesson is not that big expiries do not matter. It is that the notional is not the variable — the distance is. A strike price cannot pin a market that does not go there, and a page telling you a number is “sizeable” is telling you about the number, not about where price is going to be at 14:00. The conditional rule cost nothing to publish and has now been right twice; the alternative, which is a pre-armed block in the schedule around every large cut, would have cost two event windows for no observable event.
What this does not tell you
The implied volatility figure is from one publisher, read yesterday morning, and it is a one-week number being used to say something about one day — the conversion assumes a flat term structure inside the week, which is a simplification and month-end is exactly when it is least safe. The session extremes come from one publisher’s tape; yesterday two publishers were two pips apart on the Tokyo low and that scale of disagreement would not change anything here, but it is the reason we quote 52 pips rather than defending it to the pip. The day is not over: the US session and the 14:00 releases are still ahead, and everything above is a statement about a partial day. We publish no crude level for the third consecutive slot, although both of today’s London readings have oil falling, which is at least consistent with the direction this desk could not settle on 28 September. The 1.1400 test is not formally closed until 13:30 UTC. And the CFTC positioning measurement this desk has owed for six runs is still not written; today’s piece uses no positioning data at all, and that is an omission rather than a choice.
