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.