Quantopian's community platform is shutting down. Please read this post for more information and download your code.
Back to Community
Number of shares purchased
Alex Garcia
posted

Hello everyone,

I am having an issue with selling shares. What I have done is define the number of shares as: 

number_of_shares = int(cash/most_recent_price)

and then have the algorithm purchase these shares after certain requirements are met by saying:
order(context.security, +number_of_shares) This seems to work but the problem arises when I try to sell the shares by saying:
order(context.security, -number_of_shares)

This does not seem to sell all the shares, but instead only like 7 or 10 shares and my algorithm ends up losing more money. I think my problem is trying to define the amount.

Any suggestions?

Thanks,
Alex

4 responses
James Jack

Alex,

Do you recalculate number_of_shares before selling? If so then your cash or the stock price has changed.

Suggestions: maybe use a different approach. Use order_target_value(context.security, cash) to buy and then order_target_value(context.security, 0) to sell them all. Would that work for you?

James Christopher

@ Alex

James Jack's suggestion is an excellent way to close out a currently held position. For further reading take a look at the docs specifically look at the portfolio and position objects. With the portfolio object you can get an iterable of all of your open positions keyed by SID, and you can access attributes like amount, and cost basis through the position object.

Cheers

Disclaimer

The material on this website is provided for informational purposes only and does not constitute an offer to sell, a solicitation to buy, or a recommendation or endorsement for any security or strategy, nor does it constitute an offer to provide investment advisory services by Quantopian. In addition, the material offers no opinion with respect to the suitability of any security or specific investment. No information contained herein should be regarded as a suggestion to engage in or refrain from any investment-related course of action as none of Quantopian nor any of its affiliates is undertaking to provide investment advice, act as an adviser to any plan or entity subject to the Employee Retirement Income Security Act of 1974, as amended, individual retirement account or individual retirement annuity, or give advice in a fiduciary capacity with respect to the materials presented herein. If you are an individual retirement or other investor, contact your financial advisor or other fiduciary unrelated to Quantopian about whether any given investment idea, strategy, product or service described herein may be appropriate for your circumstances. All investments involve risk, including loss of principal. Quantopian makes no guarantees as to the accuracy or completeness of the views expressed in the website. The views are subject to change, and may have become unreliable for various reasons, including changes in market conditions or economic circumstances.

Alex Garcia

@James Jack I have tried that option but for some reason it does not sell all the shares purchased at once, but instead like -7, -22, and then the rest of them. Thanks for the suggestion though, and @James Christopher, I'll take a look at that API.

Thanks again,
Alex

James Christopher

@ Alex Garcia

If you get really stuck and frustrated add me as a collaborator and I can give you some better feedback: [email protected]

About Quantopian
Careers
Community
Events
Documentation
Academia
Lectures
Status
Facebook
Twitter
LinkedIn
YouTube
Terms of Use
Privacy Policy

The material on this website is provided for informational purposes only and does not constitute an offer to sell, a solicitation to buy, or a recommendation or endorsement for any security or strategy, nor does it constitute an offer to provide investment advisory services by Quantopian.

In addition, the material offers no opinion with respect to the suitability of any security or specific investment. No information contained herein should be regarded as a suggestion to engage in or refrain from any investment-related course of action as none of Quantopian nor any of its affiliates is undertaking to provide investment advice, act as an adviser to any plan or entity subject to the Employee Retirement Income Security Act of 1974, as amended, individual retirement account or individual retirement annuity, or give advice in a fiduciary capacity with respect to the materials presented herein. If you are an individual retirement or other investor, contact your financial advisor or other fiduciary unrelated to Quantopian about whether any given investment idea, strategy, product or service described herein may be appropriate for your circumstances. All investments involve risk, including loss of principal. Quantopian makes no guarantees as to the accuracy or completeness of the views expressed in the website. The views are subject to change, and may have become unreliable for various reasons, including changes in market conditions or economic circumstances.