Why WL purchased a different number of shares than expected?
Author: ricktgolf
Creation Date: 11/26/2014 4:51 PM
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ricktgolf

#1
I tried using Wealth Lab 6.8 on the Fidelity website and ran into some problems that I hope can be explained to me.

I input a very simple rules based strategy which was 'Buy at market'. The security is UPRO. The scale is daily. The data range is 1/1/2008 to 11/21/2014. The position size is 100% of equity with a starting capital of 50,000.

The strategy results in 1 trade of 3474 shares purchased on 6/29/2009 at 14.50. Wealth Lab appears to have used the dividend/split adjusted price.

Now my questions.

When I divide 50,000 by 14.50, I get 3448 shares. Why the difference?

Wealth Lab shows a buy and hold net profit of 2,065,880.30 against a strategy net profit of 414,753.26. My strategy is essentially a buy and hold strategy, so why the big difference in net profit?

I hope this situation is nothing more than operator error, but I do need an explanation.

Thanks

Rick
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Eugene

#2
QUOTE:
When I divide 50,000 by 14.50, I get 3448 shares. Why the difference?


It's neither "unexplained" nor an "error". Consequently, vague and misleading topic title "unexplained strategy error - help please" has been corrected.

Please find explanation in the User Guide: Strategy Window > Backtesting Strategies > 100% of Equity Sizing > Basis Price.

FAQ | Position Sizing, Extensions, Miscellaneous > "I'm using 100% Equity position sizing and strategy doesn't seem to use all capital and/or there are trades not included due to insufficient capital."

Now when you divide 50,000 by 14.39 (which was the basis price in this case), you get exactly 3474 shares.

QUOTE:
Wealth Lab shows a buy and hold net profit of 2,065,880.30 against a strategy net profit of 414,753.26. My strategy is essentially a buy and hold strategy, so why the big difference in net profit?


Because you supposedly used a 5:1 Margin Factor (the trade couldn't even be entered with the position sizing settings you mention without bumping the size down or using the Position Options PosSizer).
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ricktgolf

#3
Thanks for the reply.

I guess it was operator error and I have to do a lot more reading.
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