He was a partner in his family firm, Sydney Kennedy & Co., and a senior trustee of the London Stock Exchange.
Kennedy received a testimonial from the proprietors of the stock exchange to mark his 27 years service as a trustee.
[2] Kennedy's obituary in The Times said of him that "To him as senior trustee fell the task of dealing with the complaints of the members which he always did with great tact and patience.
[4] Kennedy was a significant collector of Chinese porcelain, especially pieces from the late Ming and Kangxi periods.
[5] Kennedy acquired pieces from other notable collectors including Ernest Grandidier, Louis Huth, Alfred Trapnell, and Edward Baring, 1st Baron Revelstoke.