How do I correct the cost basis for investments?

Brechin

I have several investments whose cost basis are significantly different from what is shown on the investment company's website. How do I correct the cost basis on Quicken? I'm thinking the deviation is the result of removing assets to transfer to another account, and it is not being captured by Quicken, but I'm not sure. For instance, there's as little as $1777.78 deviation on one investment, and as much as $60570.99 on another and $52405.22 on a third. These are the only ones affected, but I have no clue how to correct the cost basis so my reports are more accurate.

Sherlock

The correct approach is to review each lot purchase and reconcile any differences.

The sledge hammer approach is to use Removed and Added action transactions to establish the desired cost basis.

Brechin

I have years of transactions. This ought to be fun. Thanks.