Appital, a liquidity discovery platform for the buy side, has integrated Citadel Securities as a liquidity provider to offer the reliability of continuous live prices.

The firm was launched three years ago to automate equities block trading for the buy side and eventually, capital markets. In order to execute large block trades, buy-side traders historically had to call high-touch sales traders to discuss whether or not to go into the market, which could lead to information leakage.

On 4 September 2026 Appital said in a statement that Citadel Securities will act as a liquidity provider, which allows significant liquidity to be discovered and executed electronically, from large-in-scale (LIS) through to multiple days’ average daily volume. A large-in-scale equities trade is an order size that is significantly larger than normal, allowing it to receive transparency waivers under  regulatory frameworks such as MiFID II in the European Union.

Mark Badyra, founder and chief executive of Appital, told Markets Media that the partnership with Citadel Securities took just over 12 months from early conversations to the development of information flows.

“Buy-side liquidity is naturally episodic,” he added. “But Citadel is there every moment and every single day, and this reliable element is key.

Badyra compared the impact to broker Robinhood unlocking the ability for retail customers to execute immediately. He added: “We are effectively doing the same on an institutional scale.”

For example, when a client sends Appital 10 large block trades, the platform can now price all of those orders for an immediate execution, which Badyra said is something that fund managers cannot get anywhere else. Historically Appital has been positioned to execute blocks which are half or more of a stock’s average daily volume (ADV), but the platform can now also help with smaller order sizes because they can be executed immediately.

“This is continuous and live, so clients are able to price any order with zero information leakage, which is unique,” said Badyra.

Brian Guckian, chief business development officer at Appital, described the partnership as a further digitization of the high-touch sales trader. He argued that the top five investment banks have a balance sheet for risk pricing, but none of that is digitized. Guckian told Markets Media: “We are creating a new type of market structure and it is a huge step change”

For example, orders would previously come onto the platform and there could be a time lag of half a day, a day or two days, so the block traded away. In contrast, there is now immediacy with a wave of liquidity constantly coming onto the platform.

The buy side may have concerns about Citadel Securities learning about their large trades. Badyra claimed that the buy side does not have to worry about Citadel joining because the information flow is in one direction into Appital. He added: “Citadel does not see anything pre-trade or even post-trade after an execution, and clients remain anonymous.”

Guckian continued that the partnership is bringing certainty and visibility to the client base as you cannot spoof on the platform. He said: “The order has to be within your EMS [execution management system], which uploads into Appital, and there is visibility on the risk price.”

Marko Taric, head of EMEA semi-systematic equities at Citadel Securities, said in a statement: “Appital is giving buy-side firms more choice in how they source and access institutional liquidity at scale, and helping them execute with greater flexibility and confidence.”

The new capability is currently being introduced via a controlled rollout to Appital’s institutional client network, ahead of broader market availability.

Growth strategy

Appital launched three years ago with four clients and a connection to one EMS, according to Badyra. He added that the platform has grown to 57 institutions, which represent about one quarter of global equity assets, and is connected to five EMSs. The platform started in UK equities and is now live across 23 European markets with connectivity into LSE Turquoise, the London Stock Exchange’s pan-European multilateral trading facility (MTF).

The platform said on LinkedIn that liquidity grew across every market cap and participation deepened in 2025. Last year Appital liquidity was up 50% year-on-year, and the average ADV for trades was four days.

“The focus is on Appital version 2, because we have the clients, the trust and the connectivity,” said Badyra. “We are bringing this all together with the continuous real-time risk ladder from Citadel Securities.”

The intention is for Appital to also cover U.S. stocks. Badyra said: “We are in discussions with a couple of ATSs [alternative trading systems] to hopefully launch in the U.S in six months.”

The long-term objective for Appital is to go after equity capital markets. Badyra said the partnership with Citadel Securities is a “step in the right direction” and added that the firm will also think about other asset classes when the time is right.

Guckian added: “We have moved from Appital version 1 being a ‘nice to have’, to version 2 becoming a utility on every client’s front end.”