Most traders blame spread widening on low liquidity or news events, but that explanation misses the structural driver underneath: dealer inventory risk. When market-makers accumulate directional positions they didn't choose, they widen spreads defensively — not to profit, but to slow incoming flow and attract offsetting orders. That distinction matters enormously for how you read intraday pricing.
The BIS Triennial Survey consistently shows that a handful of top-tier dealers intermediate the overwhelming majority of global FX volume. That concentration means individual dealer books carry significant weight. When one major bank accumulates a large long EUR/USD position through client flow, its quoted spread on the offer side expands to discourage further buying — a mechanism traders rarely account for in their entry timing models.
Research published in the Journal of Financial Economics identifies a clear intraday pattern: spreads tend to widen at the open, compress through peak liquidity windows, then widen again approaching the close as dealers reduce risk before overnight book resets. This isn't random — it's inventory lifecycle behaviour. Traders who map their execution against these structural windows historically see measurably different fill quality across the same strategy.
One analytical framework traders apply is tracking bid-ask asymmetry across session transitions — specifically, whether the offer or bid side is widening disproportionately. Persistent offer-side widening historically coincides with dealers carrying long inventory; bid-side widening suggests the reverse. Combining this with volume-at-price data creates a cleaner picture of where dealer pressure is concentrated. For deeper structural context, bid-ask spread mechanics on Investopedia, the academic grounding behind market maker inventory models on Wikipedia, and Investopedia's explainer on dealer markets all provide solid foundational reading.
Spreads are never neutral — they carry a signal if you know how to read the asymmetry behind them.
This content is for educational purposes only and does not constitute financial product advice. Past performance is not indicative of future results. Profit Logic Ltd (ACN 688 669 936) accepts no responsibility for errors or omissions in this content or anywhere on this website. Always seek advice from a licensed financial adviser before making investment decisions.