See detail below, your basis in the 7 shares of Charter is: what you paid for the AOL stock, less the money you got on the merger with Charter, which would have been $115 X 16 ($1,840).
You bought 50 shares of AOL and then they became 16 shares of TWC, is that correct?
If so, the cost basis of the 16 shares of the TWC is what you paid for the 50 shares of AOL in 1999.
Time Warner effected a 1-for-3 reverse stock split on March 27, 2009, so the 50 shares would have become 16 shares.
Generally, the aggregate tax basis of the Time Warner Inc. common stock equals the aggregate tax basis of the common stock held (excluding the portion of such basis allocated to the fractional share), and the holding period includes the holding period of the Historic TW Inc. common stock.
source: http://ir.timewarner.com/phoenix.zhtml?c=70972&p=irol-faq_pf
So then if everything got exchanged to the 7 shares, then the cost basis of the 7 shares is what you paid for the AOL stock, less the money you got on the merger with Charter, which would have been $115 X 16 ($1,840). See below for the detail.
Charter Communications, Inc. announced that it has closed its previously announced transactions whereby, it has combined with Time Warner Cable Inc. Subject to the election described below, TWC stockholders will receive either $100.00 in cash and shares of common stock of the new public parent company, which has been named “Charter Communications, Inc.,” equivalent to 0.5409 shares of legacy Charter, for each share of TWC common stock (“Option A” consideration) or $115.00 of cash and Charter shares equivalent to 0.4562 shares of legacy Charter for each share of TWC common stock (“Option B” consideration).
Source: http://www.schwabpt.com/public/file/P-9094313/SPT013597.pdf
Your purchase date will be the date in 1999.
