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Iterating Through Every SID to Screen all Stocks

Can I run a for loop from 0 to 45526, then plug each value in as an SID, check if that stock meets my requirements, if so append to a list, if not move to the next stock? Is there a better way of doing this?

8 responses

This should be possible, but it isn't. Both sid(N) and symbol(SYM) require a constant literal, and throw an error if they get a variable or expression.

Shoot, there goes my plan to backtest all possible pairs trading combinations.... (which I am sure has been done by Wall Street quants).


I think Simon was searching for all pairs trading but gave up some time ago (there is a thread somewhere...). I suspect finding the needle in the haystack is harder than it appears.

As for symbols (in research), Grant had originally used the following:

import zipline.api

s = range(1,100000)  
stocks = zipline.api.symbols(s)  
sids = [stock.sid for stock in stocks]  

But this currently fails for me.

Doing get_pricing for all sids kills the server, as you might expect. Doing 100 at a time can work though.

So no one has been able to check all stocks? Can any Quantopian employee comment?

It's a computing/server limitation
(I believe the limit is up from 200 to 400 now?)

You will indeed run into server limitations if you try to run this is a notebook. We're working to make this easier; to unlock a new slew of analyses and algorithms by screening and filtering criteria. This is a teaser of what's to come. This is active on our radar.

And you can now trade 500 securities in your algorithm, up from the earlier 200 limit.


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What happened to zipline.api.symbols?

In the research platform, something like this is doable:

It should be feasible, then, to copy-and-paste a subset to securities into the backtester (or you could run the backtest right in the research platform). The actual limit is greater than 500 securities. Somewhere, I showed that the limit is actually 500 added per day, using update_universe(). So, within 5 days, 2500 securities could be in your universe.