Daniel Nehren joins Barclays with remit for development of algorithmic trading product, model-based business logic.
Market maker will become an equities SI in order to meet demand for additional sources of liquidity.
OANDA appoints global head of trading and quantitative analytics in New York.
The move is a sign that fund managers are also looking to reduce their derivatives exposures.
Blackrock's former global head of securities lending has joined Citadel as a COO in its equities division.
The move could radically shake up the hold of traditional bank players in European market making.
Buy-side companies with less regulatory constraints could see a greater role in market making.
Citadel's Hamill says it has taken up the slack from some banks which have lost their appetite to provide liquidity.