How risky is that?

This chart and the one following show the output from running Monte Carlo simulation. What is Monte Carlo simulation?
It compares a scenario where £2m is switched from a deposit account into equities with a scenario where the switch does not take place (the do Nothing scenario).

Do Nothing is less risky as can be judged by the greater height of the bars and more concentrated set of outcomes.

This chart presents the same data as in the previous chart but in a way that makes it easier to assign probabilities. For example, reading down the black line from top to bottom, 900 times out of the 1,000 times the simulation was run, the LifeStyle Index (LSI) was 80% or higher, 720 times out of 1,000 it was 100% or higher (from this, I think it reasonable to say that there is about a 70% chance of achieving financial independence by age 75), 500 times out of 1,000 LSI was 120%, and so on. Also, you can see that the red and black lines cross at about 820. From this I think it reasonable to say that about 80% of the time this client will achieve a better outcome from making the switch of £2m from deposits into equities – and about 20% of the time he will be worse off having made the switch. The greater steepness of the black line indicates that the Do Nothing scenario is less risky, i.e. the actual outcome is likely to be fairly close to the projected outcome.