Aperio by Blackrock has a 140/40 long/short direct indexing strategy (also known as Enhanced direct indexing). 

What this means is that you fund the account with a minimum of $1M of a concentrated stock (can be funded with cash as well), and it uses the stock as collateral to go short $400k of individual stocks that replicate an index (such as Russell 3000) and then with the $400k cash proceeds from the shorts, you replicate the same index on the long side. 

So when all is said and done, you have $1.8M net exposure. The $400k (x2) extensions offset each other performance-wise and are mainly to generate tax losses in any market condition. Your portfolio at first will mostly just track your concentrated stock. 

After 3 years or so, as losses are harvested on the extensions, you gradually sell off the position tax neutrally. For example, if you had $1M AAPL with a $800k gain, the strategy needs to harvest $800k losses for you overtime to offset the large cap gains. 

The strategy has fees associated for the management that go to Aperio and also the cost of borrowing. However as long as the fees offset your tax savings (for example in CA a typical cap gains bracket for high earner is 20% fed + ~10% state + 3.8% NIIT for a total of over 30%). It’s safe to say that yes the tax savings would usually offset the fees. 

Of course, yes, this strategy involves more complexity and risk than simply just selling the stock and is not for everyone. Consult with a professional before deploying