TopBuild (BLD) is down about 3% to $475.76 as investors reprice the announced acquisition by QXO (QXO) and the merger-arbitrage spread widens. The deal gives TopBuild holders an election of $505 in cash or 20.2 QXO shares, subject to proration that targets roughly 45% cash and 55% stock overall, making BLD’s day-to-day trading highly sensitive to QXO’s share moves and to changing expectations for the probability and timing of closing.

The transaction values TopBuild at roughly $17 billion and is structured as a cash-or-stock election with proration, so the “headline” $505 doesn’t automatically become the traded price. As the market updates assumptions on financing, regulatory and shareholder approvals, and the ultimate mix of consideration delivered, BLD can drift below the nominal offer value—especially when QXO stock is volatile—because the stock alternative (20.2 shares) and the cash cap create a variable implied value that arbitrage funds continuously hedge and rebalance.

A new analyst action pushed the deal discussion back into the tape: JPMorgan downgraded TopBuild after the QXO agreement, highlighting the mechanics of the consideration and the stock’s jump after the announcement, which can encourage profit-taking and spread trading. With BLD now trading below the fixed cash election amount, today’s decline reads as more about deal-spread dynamics than a sudden change in TopBuild’s standalone fundamentals.

Key near-term drivers include QXO share volatility (which directly affects the value of the stock election), any updates on financing commitments and the shareholder-vote timeline, and regulatory review pace. If QXO stock weakens or the market assigns more time-to-close or higher risk to completion, the spread can widen further; if milestones clear cleanly, BLD typically tightens toward the implied consideration value.