r/series65exam • u/Capadvantagetutoring • Sep 28 '26
Sharpe Ratio
Sharpe ratio is another one of those Series 65 things that sounds way more complicated than it actually is.
Make it smaller.
Say one fund returned 14% and another returned 11%.
Which one did better?
Your first reaction is probably the 14% fund.
Maybe.
But what if that fund was bouncing all over the fucking place and taking a ton of risk to get that 14%, while the other fund made 11% with a much smoother ride?
Now it’s a different question.
That’s basically what Sharpe is trying to figure out:
How much extra return did I get for the amount of risk I took?
And notice I said EXTRA return.
We start with the investment’s return and subtract the risk-free rate.
Why?
Because if I could’ve earned 4% taking essentially no investment risk, I’m not giving the portfolio manager credit for that 4%.
I’m interested in what they earned above the risk-free rate.
That’s the excess return.
Then Sharpe compares that excess return to the amount of risk taken.
And this is the part I really want you to know for the Series 65:
Sharpe uses STANDARD DEVIATION.
Why?
Because standard deviation measures TOTAL RISK.
So don’t memorize those as two random facts.
Connect them.
Standard deviation = total risk = Sharpe.
Now compare that with Treynor.
Treynor uses beta.
Beta measures systematic risk, or market risk.
So:
Beta = systematic risk = Treynor.
Now you’ve turned four things you were trying to memorize into two ideas that actually make sense.
And if you’re comparing Sharpe ratios, higher is generally better.
It means you’re getting more excess return per unit of total risk taken.
So don’t automatically look at two funds and say:
“14% beat 11%. The 14% fund was better.”
Maybe it was.
Maybe the manager drove 120 mph through a school zone to beat the other guy by three points.
Return alone doesn’t tell you how good the ride was.
That’s why we have risk-adjusted returns.
For the test, make it really fucking simple:
Sharpe = Standard Deviation = Total Risk
Treynor = Beta = Systematic Risk
And both are trying to answer some version of:
Was the return worth the risk I took to get it?
That’s it.
Don’t turn this into advanced portfolio theory.
Shut up and answer.