This bill would permanently cut in half (from 10 years to 5 years), the length of time that S corporations have to pay the built-in gains tax, commonly referred to as the "BIG tax." S corporations, according to the IRS, "are corporations that elect to pass corporate income, losses, deductions, and credits through to their shareholders for federal tax purposes." They generally don't pay corporate taxes and are limited to 100 shareholders. C corporations, on the other hand, are taxed separately from, and in addition to, their shareholders. When an S turns into a C, or acquires assets from a C, they have to pay the BIG tax.
The same reductions would also be applied to regulated investment companies and real estate investment funds.