The X-50 Index
Tracking the 50 most significant private companies shaping the global economy — private markets made transparent
Index Performance
X-50 Index Value
2,001
+100.1% YoY
X-50 Market Cap
$5.26T
+90.6% YoY
Global Private Market
$8.93T
+23.2% YoY
X-50 Concentration
58.9%
+20.9pp YoY
Data as of Q1 2026. Base value = 1,000 (Q1 2025). Global market total includes CB Insights unicorns + non-CB private companies + valuation corrections.
Top 10 Constituent Companies
SpaceX
Aerospace & Defense
CVE
$1,250B
Weight
23.8%
FVS
IBS
OpenAI
Artificial Intelligence
CVE
$852B
Weight
16.2%
FVS
IBS
ByteDance
Social Media / AI
CVE
$550B
Weight
10.5%
FVS
IBS
Anthropic
Artificial Intelligence
CVE
$380B
Weight
7.2%
FVS
IBS
Mars Inc
Food / Pet Care / Confectionery
CVE
$160B
Weight
3.0%
FVS
IBS
Stripe
Fintech / Payments
CVE
$159B
Weight
3.0%
FVS
IBS
Reliance Retail
Retail / E-commerce
CVE
$143B
Weight
2.7%
FVS
IBS
Databricks
Data / AI
CVE
$140B
Weight
2.7%
FVS
IBS
Waymo
Autonomous Vehicles
CVE
$126B
Weight
2.4%
FVS
IBS
Bloomberg LP
Financial Data / Media
CVE
$120B
Weight
2.3%
FVS
IBS
Index Methodology
The X-50 Index uses a modified cap-weighted methodology matching the NASDAQ-100 concentration constraints. Companies are ranked by their Composite Valuation Estimate (CVE) derived from a multi-source data hierarchy.
50
Constituents
CVE
Valuation Method
4
Data Source Tiers
Q
Reconstitution
Weighting
Modified cap-weighted with NASDAQ-100 identical concentration constraints. Raw weights are determined by each company’s CVE as a proportion of total index CVE, then adjusted by multi-layer caps: no single company may exceed 24% (capped to 20%), and the aggregate weight of all companies above 4.5% cannot exceed 48% (reduced to 40%).
Composite Valuation Estimate (CVE)
Since private companies have no real-time market price, the CVE is calculated from a hierarchy of data sources, weighted by confidence:
| Tier | Source Type | Description |
|---|---|---|
| Tier 1 | Secondary Market Transactions | Actual buy/sell prices on platforms like Forge, Hiive, X-Launch |
| Tier 2 | Primary Funding Rounds | Post-money valuation from most recent equity round |
| Tier 3 | Credible Media Reports | Specific valuation cited in Bloomberg, CNBC, TechCrunch, WSJ |
| Tier 4 | Mutual Fund Quarterly Marks | SEC N-PORT filings from Fidelity, T. Rowe Price, etc. |
Index Calculation
The X-50 uses the same divisor method as the S&P 500 and NASDAQ-100. The numerator is the capped-weight-adjusted total market cap, and the divisor is a scaling constant set so the base value equals 1,000 at launch. The divisor is adjusted whenever constituents change to ensure the index level remains continuous.
Eligibility Criteria
Companies must be privately held (not listed on any regulated exchange), genuine operating companies generating revenue, VC/PE-backed or independently operated, with at least one valuation data point within 18 months. Government-controlled entities and companies in bankruptcy are excluded. Companies ranked 51–60 by CVE form a buffer zone for replacements.
Reconstitution Schedule
Full reconstitution occurs quarterly in March, June, September, and December. The process includes universe refresh, CVE data collection, ranking and capping, and publication of constituent changes 30 days in advance. Companies are removed when equity shares begin trading on a regulated exchange (IPO, direct listing, or SPAC merger).
Supplementary Metrics
Published alongside the index for informational purposes: Funding Velocity Score (FVS) measures the pace and size of recent funding activity. Institutional Backing Score (IBS) measures the breadth and quality of institutional investors. Both scored 1–10.
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Disclaimer: The X-50 Index is for informational purposes only and does not constitute investment advice or a recommendation to buy or sell any securities. Past performance is not indicative of future results.