Did the 1099-B report the cost basis used to calculate to $2.98 gain(loss)? If the answer is "Yes", I would not recommend taking the time and effort to file an Amended return. The unreported income is too low to result in any meaningful change in your tax return, and would not justify either your efforts or the IRS's efforts to process.
If, however, the gross sales proceeds amount was significant (> $100 ?) and the cost basis was not reported to the IRS, then you would be subject to tax on the total proceeds.
The IRS does require you to report all of your income on your tax return.
You can amend your returns to add this 1099-B and report the cost basis. If you decide to amend, see: How to Amend (Change or Correct) a Return You Already Filed
If you don't report the 1099-B the IRS may send you a Notice of Proposed Tax Increase later this year, and use the total proceeds to calculate the additional tax due. The same process is usually followed by states.
It isn't an audit, but a proposed bill for the tax on that 1099-B income, plus any interest or penalties. They do all the calculations and provide a payment voucher if you agree to the change. You can amend your return to report the income and cost basis OR you can elect to pay the proposed increase in tax.
