XLK and VGT are the two most popular technology sector ETFs, but they track different indexes with different methodologies. For a sector that dominates most portfolios, understanding these differences matters.
Index Methodology
XLK tracks the S&P Technology Select Sector Index, which holds approximately 65 stocks from the S&P 500's technology sector. VGT tracks the MSCI US Investable Market Index Information Technology 25/50, which includes over 300 technology stocks spanning large, mid, and small caps.
The "25/50" in VGT's index name refers to concentration limits: no stock can exceed 25% of the index, and all stocks above 5% cannot collectively exceed 50%. XLK has its own capping rules based on the Select Sector methodology.
Holdings Comparison
The top holdings overlap significantly — Apple, Microsoft, and Nvidia dominate both funds. Where they differ is at the bottom: VGT includes hundreds of smaller tech companies that XLK excludes. This gives VGT marginally better diversification within the technology sector.
Performance
Returns are closely correlated since both are dominated by the same mega-cap tech stocks. Performance differences in any given year rarely exceed 1-2%. The divergence comes from different capping rules and VGT's small-cap inclusion, which can help or hurt depending on whether small-cap tech is outperforming. Check XLK vs VGT comparison data for current performance.
Which to Choose
VGT provides broader tech exposure with more mid and small-cap names. XLK provides concentrated large-cap tech. Both charge essentially the same fee (0.09% vs 0.10%). If you want pure large-cap tech, XLK works. If you want the full technology sector including smaller companies, VGT is better. Visit our education center for more on sector investing.
