/etf-overlap

Cosa fa. Misura la sovrapposizione di titoli tra ETF (rischio concentrazione nascosto).

Quando usarlo. Per evitare doppioni quando combini più ETF.

Argomenti. ETF1 ETF2 [ETF3] oppure lascia vuoto per gli ETF in portafoglio

Esempio. /etf-overlap VOO QQQ

Cosa restituisce. Percentuale di sovrapposizione e principali titoli in comune.

Come funziona

Quando lanci /etf-overlap, Dexter non esegue codice fisso: invia all’AI la prompt qui sotto — il segnaposto {arg} viene sostituito con ciò che scrivi dopo il comando — e l’agente la esegue chiamando da sé gli strumenti necessari. Vedi Come funzionano i comandi per le convenzioni comuni (chiamate in parallelo, anti-allucinazione, fasi, widget di chiusura).

Strumenti che può usare: portfolio_get, web_search, web_fetch, dispatch_agent.

Flusso/visualizzazione: può lanciare sub-agenti di ricerca in parallelo (dispatch_agent).

Prompt completa

È la prompt esatta inviata all’AI quando usi il comando (sostituendo {arg}).

ETF holdings overlap analysis.

## Phase 1 — Identify the ETFs
If "{arg}" is not empty and not literally "{arg}": use the provided tickers.
Otherwise: portfolio_get → extract ETF tickers from the positions. If <2 ETFs found: say so and stop.

## Phase 2 — Fetch holdings (per ETF)
web_search: "{ETF} top holdings 2026 site:etf.com OR site:justetf.com OR site:ishares.com OR site:ssga.com"
web_fetch the first result. Extract the top 10-20 holdings with weights.

## Optional fan-out
Phase 2 is independent per ETF. You MAY emit one dispatch_agent (subagent_type="general") per ETF IN THE SAME TURN — each does web_search + web_fetch of its own holdings page and returns the top 10-20 holdings with weights — so the raw page text stays out of your context. Then compute overlap and concentration (Phases 3-4) on the returned results. Each sub-agent prompt must be self-contained (the ETF ticker, what to extract).

## Phase 3 — Overlap calculation
- Find holdings present in 2+ ETFs. For each: weight in each ETF.
- Effective combined exposure: sum of (weight in the ETF × the ETF's share of the portfolio if from portfolio_get, otherwise treat as equal weights).
- Overlap % = shared holdings / total unique holdings.

## Phase 4 — Risk assessment
Thresholds:
- Overlap <20%: LOW — excellent, genuinely distinct exposure
- Overlap 20-40%: MEDIUM — manageable, some redundancy
- Overlap 40-70%: HIGH — significant duplication, consider consolidating
- Overlap >70%: VERY HIGH — near-duplicates, strong case to drop one
Flag every holding with effective combined exposure >5% (single-stock concentration risk).
Flag every sector with combined exposure >25%.

## Output
### Overlap Analysis: {ETFs}
| Holding | Weight {ETF1} | Weight {ETF2} | Effective Exposure | Risk flag |
|---------|---------------|---------------|--------------------|-----------|
[top 10 overlapping holdings]

### Summary
- Overlap score: X% (LOW / MEDIUM / HIGH / VERY HIGH)
- Most concentrated holding: [ticker — X% combined]
- Most concentrated sector: [sector — X% combined]

### Recommendation
If HIGH/VERY HIGH: identify which ETF is cheaper or better-performing → consolidation suggestion.
If LOW/MEDIUM: confirm complementarity. Note whether same-category overlap is avoidable.