Chi-Delta, a non-displayed order book of trading venue Chi-X Europe, was Europe’s largest dark pool in November, with more than a quarter of all the continent’s reported dark liquidity by turnover.

According to Thomson Reuters’ Equity Market Share Reporter (EMSR), 27.28% of dark order book activity – trades placed and executed off exchanges – was claimed by Chi-Delta, which launched in May on the back of a swift rise of the multi-lateral trading facility that has competed with the traditional exchanges.

Liquidnet Europe took second place, edging just over a fifth of market share at 25.02%, followed by BATS Europe, an arm of the US trading platform firm that has also battled the established venues this year, at just over 17%.

Turquoise, an MTF co-funded by a number of financial institutions, claimed 10.68%.

Chi-Delta traded EUR2.95 billion in November, up 10% over the previous month’s turnover. Participants achieved an average price improvement of 5.74 basis points in November by trading on Chi-Delta, accoding to the firm, leading to aggregate price improvement savings of EUR2.87 million for Chi-X Europe’s non-displayed trades. Non-displayed liquidity represented 3.28% of all trading activity transacted on Chi-X Europe by value in November.

Hirander Misra, COO of Chi-X Europe, said: “This success has been built on the proven liquidity discovery and price improvement opportunities offered in our visible order book, which are now also being realised in the Chi-Delta non-displayed order book whilst minimising market impact. This provides our trading participants with the opportunity to achieve real alpha in Chi-Delta with ultra low execution costs.”

Dark pools emerged as an area of significant debate this year, particularly in light of regulatory pressures for greater transparency in trading and asset pricing. A trader can sell a large volume of securities through a dark pool in chunks to avoid moving the market, which only learns of the transaction from the resulting price of the purchase.

Securities firms sponsor the largest dark pools to execute the orders of their customers and proprietary orders of the firms.

Critics say this service reduces the openness of exchange trading and gives some practitioners a competitive advantage. The development of dark pools this year culminated in recent review by the US Securities and Exchange Commission. On 21st October the commission voted unanimously to propose measures intended to increase transparency of dark pools so investors get a clearer view of stock prices and liquidity.