Question to the HM Treasury:

To ask the Chancellor of the Exchequer, what information her Department holds on the total market value of (a) cash and (b) stocks and shares ISA holdings in each of the past five tax years, broken down by investor income bracket.

Information on the total value of ISA subscriptions, the total market value of ISAs, and the number of ISA holders and subscribers broken down by income bands is available in HMRC’s Annual Savings Statistics.

https://www.gov.uk/government/collections/annual-savings-statistics