Couple more. Also, a listener question. Long-term listener, shares the same name as me, Moritz.

He's asking you how you go about changing your systems over time and how you modify systems,

how you detect decay and, you know, obviously, you know, those are those are subjective decisions I'd say and it's the

discretionary thing that even systematic traders need to admit that they're doing which is fine

is there anything else that you're doing on discretionary basis I mean in terms of

changing the system I try and change it as little as possible.

I think there's probably a bias in institutional world at least that this was my experience

towards changing systems too much. So if you say well I've got a 40 year back test

and I've now got another

year of data, is that really going to change my mind very much?

If I was to refit the system and then compare the parameters and say, well, they've changed,

yes, but on a statistical basis, have they really changed that much?

No, probably not.

So ideally, I'd only be changing the system probably when I was introducing something new into it. So if I have a new kind of trading rule or a new instrument, that that obviously

means that the capital has to be redeployed. And to be honest, actually, over the last few years, I've mostly been taking

stuff out and that's not been because I've joined the Club of Neals and saying that fewer

instruments is better.

It's been exogenous things like the fees on market data being increased. As an individual trader, I couldn't

justify paying the higher fees. It's been actually, there is one perhaps more interesting

example, which is when volatility has fallen too low in a particular instrument. It was the

two-year German bond future, the Shats, and the volatility had reduced to a level

where basically the trading costs on a risk-adjusted basis would just exploded, and the size

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