DIY direct indexing for Large capital gains ($450k+)

My situation is that I have large cap gains from selling AMD (cap gains alone of 450K+ in 2026) with a mix of long term and short term sales. I have sold a bit too much, because 1) I am moving to a higher tax state with much higher W2 income in the latter half of 2027, 2) I am hoping to buy a house within the next 2-3 years and 3) did feel that the market was running hot/euphoric.

I feel overwhelmed by the impending tax bill and was reading up on direct indexing offered by Fidelity or PGIM. This made me think about doing a DIY version by buying a wide range of indices and stocks in different sectors as well as materials, crypto etc. Every month, I would sell the losers and repurchase a similar ETF/stock, keeping the winners until long term when I would sell to fund my house purchase. 

The goal is to cancel out short term gains as much as possible this year while diversifying to minimize my risk. I have another window in the first half of 2027 to realize my gains in a relatively low tax environment, so some tax deferment this year could be beneficial. 

1.Does this sound like a reasonable plan and theoretically beneficial for me in my situation? When I run basic math, I see this strategy winning against putting all of my cash into treasuries/SGOV in choppy/neutral and bull markets. In a bear market, SGOV would win short-term but diversified TLH investing partially offsets losses through tax loss harvest while maintaining market participation with possible recovery in the future.

2. If so, the big question is exactly what mix to buy? A balance of ETFs in various sectors (semis, healthcare, finance, insurance, consumer defensive, communications, consumer cyclical, industrial, energy etc) would be important obviously. And I plan on throwing in a good number of representative stocks like WMT and Autozone which would be resilient in case of sector rotation or a bear market (and in an attempt to create enough dispersion which is a potential pitfall for DIYing). Anything else I should consider like materials (e.g. gold, plat), foreign markets, storage REITs etc?

The proportions would be something that I would need to figure out too. For example, how much to put into something like SOXX where I already have good exposure with 25 percent of my portfolio remaining in AMD?

Someone even suggested setting aside some % for lottery ticket trades like short term OTM options. Not sure if I am willing to go that far…but it reflects my current position where I coudl be slightly more risk-taking at least until end of this year.

3) How much of my cash (~750k) should I keep in SGOV/cash? Obviously, I should have enough to pay off my taxes (I am planning to utilize the safe harbor rule to avoid penalties) next year, in addition to holding some reserve for re-entry of AMD if it experiences a significant dip. So I am thinking around 250K.

Thank you!