Month-End Flows: When Portfolios Rebalance the Currency Market

[Fairman]

Month-End Flows: When Portfolios Rebalance the Currency Market

At the end of each month, and especially each quarter, large investors rebalance their portfolios. These adjustments can produce currency flows that have nothing to do with news.

The mechanism is straightforward. Suppose a US pension fund holds European stocks, and European stocks have outperformed during the month. Its allocation to Europe is now larger than planned. To restore balance, it sells some European assets and converts euros back to dollars. Multiplied across many funds, such flows can nudge exchange rates.

The effect is most visible around the London 4 p.m. fix, a benchmark rate set at that time each day, when many large orders are executed. On the last trading day of the month, price sometimes moves sharply in the hour before the fix.

The direction is hard to predict. Estimates by banks of rebalancing flows are published, but they are imperfect, and the effect can be offset by other flows.

For retail traders, the practical lesson is to expect odd moves around the month-end fix, and to avoid reading too much into them. A sharp move at 4 p.m. London on the last day may reverse the next morning.

Spreads and liquidity can also behave unusually around the fix.

Practical step: mark the last trading day of each month and the 4 p.m. London time on your chart, and note how price behaved over six months.

[Fairman]

Quarter end is usually the bigger one. Some banks publish rough rebalancing estimates a few days before, and while they're often wrong, they at least tell you whether a big flow is expected in one direction.

[Fairman]

For scalping, I just avoid holding anything through the hour before the 4pm London fix on the last day. Moves in that window can be big and fast, and they often reverse the next session.

[Fairman]

One more thing: month end can fall on a Friday, which stacks rebalancing on top of weekend position squaring. Those afternoons can get choppy, so I'm happy to close early and wait for Monday.