As Democrats seek ways to cover their $3.5 trillion spending package, lawmakers are floating a new limit on a popular write-off for technology start-ups and other industries. Qualified small business stock allows founders, early employees, and investors to write-off up to 100% of stock gains, exempting up to $10 million or 10 times their initial purchase price when they sell. To be eligible, a corporation must have less than $50 million in gross assets when issuing the qualified small business stock, and non-corporate shareholders must hold the investments for at least five years. Currently, there is a 50% exemption for stock issues after August 10, 1993. The percentage jumps to 75% for assets received after February 17, 2009. Investors may claim the 100% exemption for stock issues on September 27, 2010, or later. Qualified small business stock has been particularly valuable for early investors in technology start-ups. With limited physical assets, these companies often fall below the $50 million thresholds while worth significantly more.