Savings must be held in cash in a personal bank/savings account in the name of the applicant, their partner or the couple jointly.
The savings can be from any legal source, including a gift from a family member or other third party, provided the source of the cash savings is declared.
The applicant and/or their partner must confirm that the money, which cannot be borrowed, is under their control and evidence that it has been held in their bank account for at least the 6 months prior to the date of application.

However, it is possible under certain conditions that the period of 6 months prior to the date of application can be reduced by the amount of time during that period that the funds were held in the form of investments, stocks, shares, bonds or trust funds.

For this to work, those investments must have been in the ownership and under the control of the applicant, their partner or both jointly for at least the period of 6 months prior to the date of application, and also that the value of the investments, stocks, shares, bonds or trust funds at the beginning of the 6 month period was at least equivalent to the amount of the cash savings relied on in the application.

Don't forget that cash savings can also be combined with employment income, pensions and other non-employment income.
But cannot be combined with self-employment income, or with income from employment as a director of a limited company.

Without combining cash savings with any income the amount needed to be shown for visa application purposes is £62500 min

Hope this helps