I expect he has multiple accounts.

For example, this TDAmeritrade account is his taxable account mainly for trading. Besides that, he might have IRA account(to hold all kinds of bonds, IBond/TIPS), 401K/403B account, 529/Tuition prepayment, life insurance policy, long term care insurance poilcy (just for tax diversation purpose). Furthermore, he could consider owning rental investment(possible farm land, forest), oil/gas limited partnership, precious metal and foreign investments(including foreign currency). If I guess wrong, and the majority(more than 50%) of his investment is indeed in this TDAmeritrade account, I strongly suggest him immediately seek high quality professional advisery(including estate plannng and tax). Otherwise, the loss could be more than "一成皮". Many years ago, I was at the right time and right place to ride through Netscape, JDSU, QCOM and CSCO. At one time in 2000, most of Wall Street analysts believed Cisco's capitalization could eclipse 1 Trillion within a year. Today, 11 years later, Cisco's market cap is just above 100 billion.

Last thing, I can NOT give professional advises because I'm not in that business.