USA How to calculate the market cap of a company before and after IPO

[IteRseco]

Hi, when I calculate the market cap of a company before IPO, I just go to the latest S-1 form and find "Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted".

Then, I multiply the IPO stock price by the number of shares I found.

For an after IPO company, I just go to the latest 10-Q form and find "Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted".

Then, I multiply the current stock price by the number of shares I found.
Is my method correct?

However, I always find out that the market cap calculated by myself is a little bit less than the market cap provided by the trading platform. Is this because new shares have been issued since the S-1/10-Q report?

Thanks

 

[MoralesTax]

You're using historical data; whereas, the trading platform is using "real-time" data. Your method is not necessarily wrong, but you're not factoring current market value of the shares, which differs from the US GAAP numbers you're using by looking at S-1/10-Q reports.

 

[IteRseco]

What do you mean "you're not factoring current market value of the shares"? I always use the latest stock price. My explanation now is the company issued more share on the IPO day. For example, Affirm went public on Jan. 13th. However, according to SEC filing here:

EDGAR Search Results

www.sec.gov

In the FORM S-8, Affirm issued more shares in addition to the shares announced in S1. I have not done the calculation myself. But I think this explains the difference. I missed the shares in Form S-8.