Index Weighting Methodology
The mathematical engine balancing thematic purity, physical constraints, and portfolio liquidity in low-Earth orbit compute infrastructure.
1. Strategic Category Allocations
GOSIX structures its exposure across six physical bottleneck categories. Each category represents an indispensable component layer of the space data grid, with its strategic allocation target defined algebraically by variables S_s (where s ∈ {1..6} and ∑ S_s = 100%).
2. The Weighting Equation
Within each segment s, a constituent i's raw score is calculated using its natural log-scaled USD market capitalization, weighted by qualitative metrics measuring physical bottleneck criticality and thematic focus:
Where the input parameters are defined as:
- Market Cap: The company's total equity valuation converted to USD. A floor of 10⁷ ($10,000,000 USD) is enforced to ensure positive values and filter shell companies.
- Segment Criticality (C_i,s): A qualitative coefficient between 0.0 and 1.0 representing how vital the company's IP or engineering output is to solving that specific physical segment bottleneck.
- Thematic Concentration (F_i): A factor between 0.0 and 1.0 reflecting the percentage of enterprise revenue or R&D capital dedicated to space-grade/vacuum environments, favoring pure-plays over diversified conglomerates.
Raw constituent weights are normalized within each segment to sum to 100%:
3. Multi-Tiered Portfolio Capping Rules
To comply with institutional risk boundaries and prevent thin-liquidity execution errors, GOSIX implements a rigorous four-tier capping framework:
40.00%
Maximum allocation for a single company within its mapped segment, preventing local monopolies from capturing the risk profile.
8.00%
Maximum total index weight for any single constituent in the core semiconductor, optical, or power segments.
4.00%
Maximum global weight for macro-launch or logistics anchors (e.g. SpaceX) to ensure the index focus remains on hardware compute.
0.50%
Maximum global weight for thin-float small-caps to prevent execution bottlenecks. To avoid turnover whiplash, membership in the micro-cap tier is governed by a two-sided hysteresis band: a constituent not currently uncapped (outside the index, or already capped at 0.50% in the prior composition) must rise above a $350M market cap to escape the cap, whereas a constituent currently uncapped (weight exceeding 0.50% in the prior composition) is only demoted into the tier once its market capitalization falls below $250M.
4. The Biproportional Scaling (RAS) Loop
Capping a company's global weight dynamically reduces its segment contribution, dropping column sums below their targets S_s. To resolve these competing constraints simultaneously, GOSIX runs the iterative RAS Matrix Scaling Algorithm:
Initialize Contribution Matrix
Create contribution matrix: M_i,s = S_s × w_capped_i,s
Row Scaling (Constituent Caps)
If global sum exceeds its cap C_i (8%, 4%, or 0.5%), scale down its row contributions: M'_i,s = M_i,s × (C_i / W_i)
Column Scaling (Segment Targets)
Scale columns back to targets: M''_i,s = M'_i,s × (S_s / ∑_k M'_k,s)
Check Convergence & Stabilize
Repeat steps 2 & 3 until contribution matrix elements converge to a stable state within limits.