If you die holding securities with an unrealized appreciation, the appreciation escapes income tax altogether.

FORBES: Buying shelter

Yes, we figure in the tax on distributed capital gains but not on the unrealized appreciation in the fund's shares.

FORBES: How We Find The Very Best

Many companies still offer employer stock in 401(k) plans because of a tax preference called net unrealized appreciation (NUA).

FORBES: The Riskiest Stock to Own: Your Employer's

Also, if it bought Phipps Inc. stock, Gray could get stuck paying gains taxes on Phipps' unrealized appreciation if it sold down the road.

FORBES: The Tribe and the Television Stations

You may or may not be familiar with the concept of Net Unrealized Appreciation (NUA) as it relates to company stock owned in your 401(k) plan.

FORBES: One Thing You Don't Know About Roth Conversions

We would finally level the playing field between founders and investors (who escape all tax on their unrealized appreciation) and wage earners (who are subject to current tax at ordinary income rates on all of their economic income, except what little they can put into tax-deferred retirement plans).

FORBES: Guest Post: Mark to Market Taxation