Cost basis not correct
I own a private equity stock which I entered manually the shares and cost paid. Each month I enter the value increase or decrease as a "miscellaneous" income as cash. Quicken calculates the Cost Basis each month as the total value rather than the original cost I paid. My cost has never been more than what my original cost I paid and the total value has more than tripled over time. Why is the income being considered Cost Basis?