BMLL and Exponential Technology have partnered to launch XTech US Equity Flow, a product that decodes full-depth US equity order-book data into net buying and selling attributed by investor type. Announced on 2 July, it breaks flow down into high-frequency, fund and retail activity across US equity venues, turning raw microstructure data into something the order book does not directly reveal: who is behind a move, and whether a price change reflects temporary market impact or genuine repricing on new information.
The product pairs BMLL’s harmonised Level 3 order-book data with Exponential’s inference methods. BMLL supplies the substrate; Exponential builds the decoding layer on top. For BMLL, that arrangement is now a familiar one. In December 2022, FactSet drew on BMLL’s Level 3 engineering to make a better Level 2 tick-history product. Snowflake and QuantHouse used its data to widen distribution. In February, Features Analytics built trade-surveillance benchmarking on it. Each followed the same shape: BMLL provides the harmonised order-book foundation, a partner builds the application above it.Elliot Banks, Chief Product Officer at BMLL, tells Market & Alt Data Insight the firm sees its future in provision rather than what gets built above it. “Where we want to focus is on being that foundational data layer. Firms can take what they want and consume on top of it. A lot of people consume a great deal of Level 3 data; many more simply don’t want to have to process that enormous volume of data, or they’re using it in a different workflow where the years of history aren’t necessarily something they want to churn through and warehouse. Products like Exponential’s then give firms the ability to take and consume that information in a bite-sized, usable way, powered by the high-quality data we’ve produced.”
Morgan Slade, Chief Executive Officer and Head of Research at Exponential, casts his firm as the interpretation layer that sits above BMLL’s data. “BMLL has the highest-quality Level 3 data you can get access to, and we’re focused on advanced analytics built on a high-quality data substrate,” he says. “The datasets BMLL has access to are rich and complex, so the partnership brings our research team together with their high-quality data. We’re an advanced-analytics translation layer for this rich, complex order-book data.”
The consumption problem
What Exponential offers is shaped by a specific obstacle on the buy side. Firms that want to use Level 3 data often cannot get from acquisition to a working investment process inside the trial window a vendor offers.
Slade describes three tiers of buyer. Sophisticated quant firms know what they want from order-book data. A larger group knows it needs the data to compete but has no clear route to deploying it. Exponential targets that second group with pre-built flow factors tuned to a client’s investment horizon, an on-ramp designed so that a quant portfolio manager reaches working examples before a 30- or 60-day trial expires.
That framing sits against several years of sector messaging – BMLL’s own included – about democratising access to granular data. Widening access solves supply. It leaves untouched the question of whether a firm can turn the data into a decision, which is the gap Exponential is addressing.
What the signal delivers
The product’s central claim is that decoded institutional flow anticipates price. “Even off the shelf, the raw flow analytics explain about 70% of market price movement,” he says. “Level 3 data gives you a really good read on liquidity – but working with it directly takes deep technical skill. That’s the point of XTech’s flow factors, built on BMLL data: you don’t have to be a market-making expert to use them. You can just take the factors and go.”
The underlying data is historical – T+1, blended with other delayed sources and proprietary inference to approach near-real-time delivery. Clients can take the data in one-minute, hourly, daily or weekly intervals alongside T+1 and 15-minute delayed options, with advanced tiers adding HFT, fund and retail decomposition per exchange and per ticker. A discretionary manager weighing whether a live move is temporary impact or genuine repricing is doing so on inference over delayed data, not a real-time read of the book.
Foundation and phase
BMLL’s move toward being the layer under productised analytics arrives after a change in ownership. Nordic Capital acquired the firm in October 2025, in partnership with the management team and minority shareholder Optiver, a deal positioned at the time as fuel for the company’s next phase of growth.
Partnerships of this shape – a data owner supplying the substrate while third parties build and commercialise the analytics – are how BMLL now describes its own strategy. Discussing the Features Analytics tie-up in February, BMLL CEO Paul Humphrey said the firm’s expanded coverage and its position following the Nordic Capital acquisition were what allowed it to back that kind of development. The Features Analytics surveillance work and the Exponential flow product apply the same model to different ends: measurable surveillance in one case, tradable signal in the other, both built on data BMLL no longer expects clients to curate themselves.
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