There are some really good cost basis applications online that you might want to check out. Go to Yahoo and plug in
"cost basis tax optimization" to find an application that not only accurately calculates the basis but has a great tool to help you figure the best sell strategy to optimize your taxes.

I used it last March and it worked great for me. I had some sales of complicated corporate action stocks like AT&T...and it worked wonderfully for that.

If you have trouble calculating an accurate cost basis, there are great calculation applications online. One even has a unique Tax Optimization Tool to help you when you are selling so you can choose the sales methodology to declare that is most advantageous to you. You wouldn't think it makes much of a difference but in many cases it can make a HUGE difference so worth checking out. Just "google" the phrase and you'll find it. Good luck.

There is a much more precise way to calculate your cost basis. There are some great cost basis calculators online if you just google "cost basis calculator". Those require date of purchase, number of shares and you will get the cost basis as of the last trade day. Those already account for all corporate actions and events so you don't need to estimate it. You can obtain the right answer. Doesn't cost much and certainly more accurate. Good luck.

If you “lost” basis you'll be better off to use a program to calculate the basis by tax lot since it would be considered uncovered. They aren't really required to update since it would be uncovered. The software programs can be found online for a minimal fee that will calculate your cost basis and do it by tax lot.

A great way to verify your cost basis and determine the sales methodology when that time comes is to use the technology that is out there. Just plug in "cost basis calculator" in your search engine you will find it. You don't want to just guess your cost basis because the new regulations hold individual investors responsible for getting it right.

A great tool to determine sales methodology for the optimal cost basis to minimize capital gains is at www.netbasis.com.