Tim propp, cfo of thunderbird, inc., invested some of the firm's excess cash in the common shares of what he thought were three undervalued securities. at year-end, he reviewed how the portfolio of securities had done. security name cost basis market value at year-end classification microsoft corporation $100,000 $147,620 trading security pfizer, inc. 75,000 88,330 trading security boeing, inc. 50,000 58,080 available-for-sale security $225,000 $294,030