# How do you figure the cost basis of a stock if you don't have the purchase information?

**URL:** <https://boards.straightdope.com/t/how-do-you-figure-the-cost-basis-of-a-stock-if-you-dont-have-the-purchase-information/744210>\
**Category:** Factual Questions\
**Created:** [January 25, 2016, 10:01pm UTC](https://boards.straightdope.com/t/how-do-you-figure-the-cost-basis-of-a-stock-if-you-dont-have-the-purchase-information/744210 "2016-01-25T22:01:46Z")\
**Posts on this page:** 1\
**Showing post:** 6

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**Author:** ![Omar\_Little](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/omar_little/32/269_2.png) [@Omar\_Little](https://boards.straightdope.com/u/Omar_Little)\
**Post date:** [January 25, 2016, 11:08pm UTC](https://boards.straightdope.com/t/how-do-you-figure-the-cost-basis-of-a-stock-if-you-dont-have-the-purchase-information/744210/6 "2016-01-25T23:08:14Z")

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> [@friedo](#):
>
> That gets complicated very quickly with mergers, acquisitions, and share splits. There are stock research services that can figure this stuff out, though.

It’s not that complicated. All of the info. is online.

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