Lennar said that it has agreed to buy Arlington, Va.-based home builder CalAtlantic for $9.3 billion in cash and stock, including $3.6 billion in assumed debt. The combined company would have a market cap of around $18 billion.

Why it matters: The merger would create the country's largest home builder by revenue.

D.C. context: The National Association of Home Builders will oppose the House GOP's forthcoming tax bill, despite a weekend concession on itemized property tax deductions.

Bottom line: "In acquiring CalAtlantic, Lennar will have access to a new supply of developable land that can be built on quickly, which is less risky than buying large tracts of undeveloped land that could take years to get permits." – WSJ