Managers and controlling shareholders (insiders) can extract (tunnel) wealth from firms using a variety of methods. Tunneling occurs across both developed and developing markets, and impacts both trading prices and premia paid for corporate control. This article studies how effectively US' rules limit tunneling by insiders of public companies. The authors consider three broad types of tunneling: cash flow tunneling, in which insiders extract some of the firm's current cash flows; asset tunneling, in which insiders buy (sell) assets from (to) the firm at below (above) market prices; and equity tunneling, in which insiders acquire equity at below market price, either from the firm through an equity issuance or from other shareholders, often in a freezeout. The authors also examine how a broad set of rules, including corporate, securities, accounting, tax, and creditor protection rules, impact each type of tunneling. Prior law and finance literature discuss the potential anti-tunneling role of these sources, but not how they affect particular types of tunneling.