Tax-optimization equity strategy

Sch bk 1, LOS 13i, Pg 367

Under ‘Index tracking with active tax management’ it explains ‘cash from a monetized concentrated stock position is invested to track a broad market index on a pretax basis and outperform the index on an after-tax basis.’

Can anyone please explain the meaning/interpretation of ‘…a pretax basis and outperform the index on an after-tax basis’.

Thank you

you are obtaining tax alpha from the strategy.

Pre-tax returns on your strategy track index returns. - so tracking risk PreTax return on strategy - Return on the Broad market index is minimal.

But after tax returns provide you alpha.

^^ best of luck mate. I hope we clear this year. It’s worth mentioning that completeness portfolio also ends up like an index tracking after concurrent sales w/o triggering tax events.

why does this give you a tax alpha?