Gross margin is gross profit divided by revenue, the share of Upwork Inc.'s GAAP revenue left after the direct costs of running the platform, processing payments and delivering managed services are deducted.
Gross profit is revenue less cost of revenue, both GAAP lines in the income statement of the Form 10-Q and 10-K and both tagged in XBRL. For Upwork, cost of revenue is made up of payment-processing and hosting costs on the marketplace and of the cost of the work itself on managed-services contracts, where the freelancers delivering the engagement are paid out of the contract value that Upwork recognised as revenue. That mix is why the margin moves with the revenue mix: marketplace revenue is almost all margin because the fee is small and the cost of collecting it smaller, while Enterprise revenue carries the pass-through cost of delivery. A quarter in which Enterprise grows faster than the marketplace lowers the blended gross margin without anything about the marketplace changing.
Gross margin is a GAAP ratio, unlike adjusted EBITDA margin, and it sits above it: operating expenses, sales and marketing, research and development and general and administrative, are deducted after gross profit. Stock-based compensation attributed to cost of revenue is inside gross margin, so a non-GAAP version, where Upwork states one, differs slightly from it.
For the marketplace the number is a structural fact rather than a signal. Take rate says how much of each client dollar Upwork keeps; gross margin says how little of what it keeps is spent collecting it.
How Upwork Insights uses it
This term describes Upwork's own rules or product rather than a figure the index measures; the pages that do carry live figures are the stats and rate pages.