IFRA
iShares U.S. Infrastructure ETF
stock BATS ETF

That are already quite diversified with the S&P 500, some Vanguard funds, around $700,000 treasuries, Russell 1000,
We could obviously ask their advisor, but they tend to be very cautious. We are at ATH’s and not gamblers, but want to be a bit more aggressive?
Claude response -
Looking at this portfolio, your children already have a solid, diversified foundation. For $100,000 with their ages and timeline flexibility, here are some more aggressive strategies to consider:
Sector-Specific Growth Areas:
• Healthcare/Biotech ETFs (XBI, IBB) - Demographics favor long-term growth
• Emerging Markets (VWO, IEMG) - They’re underrepresented in emerging markets
• Small-Cap Value (VBR, IWN) - Historically outperforms large-cap over long periods
• International Developed (VEA, IEFA) - Their portfolio seems very US-heavy
Individual Stock Concentration:
Since they have broad market exposure already, they could allocate 20-30% to individual growth stocks in sectors they understand well - think established companies with strong moats that aren’t fully reflected in index weights.
Real Estate Investment:
• REITs (VNQ, SCHH) for real estate exposure without the down payment commitment
• Infrastructure ETFs (IFRA, PAVE) for long-term demographic plays

You can still buy ETFs but the ones you have are market weighted not equal weighted, so for example VOO is mostly the Top 10 biggest players and a little smattering of the other 490 stocks. That's not diversified. I am not a proponent of Equal Weight either but it's something to look at.
You might look at Sector funds that you are underweight like IETC, IFRA, XLF and others. It depends on your risk tolerance and your game plan.
I made my money in individual stocks not ETFs but that's going to get me down voted and I don't care. I did a lot of research and chose what I understood versus meme stocks/ETFs.