In the current climate of market volatility prompted by the COVID-19 pandemic, more and more public companies with valuable US tax assets (e.g., net operating loss carryforwards) may, or at least should, consider adopting a shareholder rights plan in order to preserve those tax assets. These plans are commonly referred to as “NOL rights plans” (or “NOL poison pills”). An NOL rights plan is a variation on the traditional takeover defense rights plan, but is designed to protect a corporation’s US NOL carryforwards and other US tax attributes, rather than simply deter takeovers and other hostile attacks not supported by the board of directors. NOLs and other tax attributes can be irreversibly limited if the corporate stock undergoes an “ownership change” (as determined under US tax principles), which can be triggered by certain acquisitions of the corporation’s stock. An NOL rights plan is intended to discourage acquisitions of the stock that might trigger an ownership change.