Mr. Halligan declined to disclose HubSpot's valuation but said public-market investors offered 18% to 20% higher prices than typical private-company investors.

WSJ: New Money Ventures to Silicon Valley

Wu, who has a Buy rating on the stock, says he attempted to value the business with a sum-of-the-parts approach, looking at the value of each major part of the business based on the valuation of comparable companies in the public market.

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