What allocation changes would most improve diversification?

I can’t give buy/sell recommendations, but I can explain where your portfolio’s concentration and overlaps are, and which allocation shifts would most reduce those concentrations.

Here are the main concentration and overlap points from your portfolio and the changes that would most improve diversification (explanation only):

Area to address	Current picture	Change that would reduce concentration
Single-company concentration	Top holding is Apple Inc. at 18,41% of the portfolio; top 5 sum to 65,64%	Reduce reliance on the largest positions by lowering the share of the top holdings or spreading that capital across more individual companies or broad exposures
Asset-type concentration	Stock is 49,09% and ETF is 31,21%	Shift some weight between Stocks and ETFs so the ETF bucket increases relative to single-stock positions (ETFs give automatic internal diversification)
Sector concentration	Technology is 39,98% of the portfolio	Move part of the Technology weight into other sectors (e.g., Financial Services, Industrials, or Healthcare) to lower sector skew
Country concentration	United States is 62,45% of the portfolio	Increase allocations outside the United States (Europe, Asia, or other regions) to lower single-country exposure
Market-cap skew	Mega Cap is 53,51% of the portfolio	Increase mid/ small cap or non-mega-cap ETFs to diversify market-cap exposure
Crypto allocation	Crypto is 8,61% (7.833,76 € €) and contributes notable volatility	Rebalancing crypto weight relative to other asset classes would reduce portfolio-level volatility contribution from crypto
ETF overlap	iShares Core MSCI World UCITS ETF and Xtrackers MSCI USA UCITS ETF 1C share many companies; combined shared value €6.104,49	Reducing duplicated exposures between ETFs (choosing non-overlapping indices or fewer overlapping ETFs) lowers double-counting of the same companies
Coverage note	Company look-through coverage is 31,13%	Be aware the look-through covers 31,13% of assets; changes based on company overlap use that coverage level

What these points mean for diversification (explanation):

• Spreading capital away from the largest individual names and from the Technology / US mega-cap concentration will lower single-stock and sector risk.
• Using broader or complementary ETFs (with low overlap) increases exposure diversity while keeping implementation simple.
• Reducing the relative weight of high-volatility buckets (crypto, single high-volatility stocks) lowers portfolio volatility contribution.

If you want, I can produce a concrete table showing: current vs. hypothetical allocations after specific shifts (assumptions stated) so you can see how top weights, sector and country splits, and volatility contribution would change.