SPI 20¶
A capitalization-weighted index of twenty large companies on the SIX Swiss Exchange without an individual constituent cap.
Core Idea¶
The roster, free-float factors and weights change under official review; historical back-calculation and the absence of the SMI’s cap distinguish the index. Eligible equities are ranked and selected under SIX rules, free-float market capitalizations determine uncapped weights and a divisor maintains continuity across corporate actions. The abstraction is therefore identified by a declared carrier, a transformation or constraint over that carrier, and an invariant that tells an analyst whether the named structure is genuinely present.
The load-bearing residual is not the broad topic of financial indices. It is the domain-specific identity fixed by the index provider and methodology version, eligible universe, constituent count, selection and review dates, free-float capitalization, weighting and cap rule, divisor and corporate-action treatment, base value and return variant are explicit.
Scope of Application¶
SPI 20 belongs to financial indices and is useful where the analyst can specify the typed financial indices carrier, including objects, relations, parameters, conventions, evidence, and comparison cases, then evaluate the index provider and methodology version, eligible universe, constituent count, selection and review dates, free-float capitalization, weighting and cap rule, divisor and corporate-action treatment, base value and return variant are explicit. The scope is broad within that domain but bounded by the need for the index provider and methodology version, eligible universe, constituent count, selection and review dates, free-float capitalization, weighting and cap rule, divisor and corporate-action treatment, base value and return variant are explicit. Descriptive index identity only; it is not investment advice.
Clarity¶
The abstraction clarifies a crowded vocabulary by making the index provider and methodology version, eligible universe, constituent count, selection and review dates, free-float capitalization, weighting and cap rule, divisor and corporate-action treatment, base value and return variant are explicit the center of the account. A claim should name the carrier, the governing operation or relation, the applicable assumptions, and the recognition test.
Manages Complexity¶
Without the abstraction, an analyst must reason directly over many local details: the carrier roles, admissibility assumptions, competing conventions, derived invariants, boundary cases, and proof or validation obligations specific to SPI 20. SPI 20 compresses them into the roles in the structural signature. That compression permits comparison across instances without erasing the variables that determine validity. It also exposes which details may be varied safely and which are constitutive.
Abstract Reasoning¶
- Identify the carrier. State what the elements, states, objects, or observations are: the typed financial indices carrier, including objects, relations, parameters, conventions, evidence, and comparison cases. Reject examples whose alleged carrier belongs to a different problem. 2. Lock the constitutive rule. Express the index provider and methodology version, eligible universe, constituent count, selection and review dates, free-float capitalization, weighting and cap rule, divisor and corporate-action treatment, base value and return variant are explicit independently of one notation or implementation.
Knowledge Transfer¶
Knowledge transfers strongly among subfields of financial indices because they reuse the typed financial indices carrier, including objects, relations, parameters, conventions, evidence, and comparison cases, Eligible equities are ranked and selected under SIX rules, free-float market capitalizations determine uncapped weights and a divisor maintains continuity across corporate actions., and type the carrier, state every parameter and convention in the definition, test that the index provider and methodology version, eligible universe, constituent count, selection and review dates, free-float capitalization, weighting and cap rule, divisor and corporate-action treatment, base value and return variant are explicit, compare the nearest accepted identity, and report counterexamples, uncertainty, and limiting cases.
Relationships to Other Abstractions¶
Current abstraction SPI 20 Domain-specific
Parents (1) — more general patterns this builds on
-
SPI 20 is a kind of Index Prime
The proposed strict upward parent is
prime:index.
Hierarchy paths (4) — routes to 3 parentless roots
- SPI 20 → Index → Search and Retrieval → Problem Space → Representation → Abstraction
- SPI 20 → Index → Search and Retrieval → Trade-offs → Constraint
- SPI 20 → Index → Search and Retrieval → Problem Space → State and State Transition → Phase Space
- SPI 20 → Index → Search and Retrieval → Problem Space → Problem Representation → Representation → Abstraction
Neighborhood in Abstraction Space¶
SPI 20 sits in a moderately populated region (53rd percentile for distinctiveness): it has near-neighbors but no dense thicket of look-alikes.
Family — Financial Risk & Market Indicators (29 abstractions)
Nearest neighbors
- Price-to-cash flow ratio — 0.90
- Buffett indicator — 0.89
- Chance-constrained portfolio selection — 0.87
- Net income per employee — 0.87
- Cash-flow-to-debt ratio — 0.87
Computed from structural-signature embeddings · 2026-09-08