Naseer Al-Khudairi worked at Credit Suisse for 20 years and will join Barclays in March.
Global asset management business at HSBC targets passive fixed income investing business with latest hire.
Investec appoints co-CEOs as three of its founding members will step down in October this year.
Squires first joined AXA in 1996 and was promoted to head of trading in 2005.
Wai Lee has previously worked at Neuberger Berman, Credit Suisse Asset Management and JP Morgan Investment Management.