Often I check an investment strategy's performance by summing the year-to-date realized gains/losses.
I take the sum of all closing(or market for unrealized) values CT, subtract the sum of all cost basises (sp?) OT, and divide that difference by the total cost basis OT. That gives me raw performance year-to-date. So in terms of percentage gain/loss:
performancePercYTD = ((CT - OT) / OT - 1) * 100
From there it can be roughly annualized into an APR performance = performancePercYTD * 365.25 / day_of_year
Question. Using the [Rule of 72][1]Rule of 72 how can one estimate:
- The doubling frequency in days
- Projected portfolio value in 90 days
- How long before at this pace, the account will reach $10000
- How long before the first sustainable $500/month withdrawal indefinitely will not deplete the principal, assuming the current growth rate continues?
- The reverse of the last question, for example, what minimum amount could be a sustainable monthly withdrawal in 24 months(730.5 days)?
It's an exercise I would like to script for daily computations, since of course variables change constantly. Thanks! [1]: http://www.investopedia.com/terms/r/ruleof72.asp#axzz1pTSvv0D0