/etf-compare

Cosa fa. Confronta due o più ETF su costo, rendimento, tracking e liquidità.

Quando usarlo. Per scegliere tra ETF simili.

Argomenti. ETF1 ETF2 [ETF3]

Esempio. /etf-compare VWCE.MI SWDA.MI

Cosa restituisce. Tabella comparativa con un verdetto finale.

Come funziona

Quando lanci /etf-compare, 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: get_etf_profile, get_stock_performance, get_technical_indicators, portfolio_get, web_search.

Prompt completa

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

Head-to-head ETF comparison.
Guard: if "{arg}" is empty or literally "{arg}", respond: "Usage: /etf-compare SPY IVV [VOO]" and stop.
Extract 2-3 ETF tickers from "{arg}".

## Data (in parallel for each ETF)
- get_etf_profile → AUM, expense ratio, category, div yield, YTD/3Y/5Y returns
- get_stock_performance → 1D/1W/1M/3M/YTD/1Y
- get_technical_indicators → RSI(14), SMA20/50
- portfolio_get → check whether the user holds any of the ETFs

Then web_search: "{ETF1} vs {ETF2} tracking difference bid-ask spread Sharpe ratio" for data not in the DB.

## Analysis

### Category alignment
- Do all ETFs track the same index or different variants? (e.g. S&P 500 vs Nasdaq vs Total Market)
- Fund family and domicile (UCITS IE-domiciled vs US-domiciled: WHT implications for EU investors).

### Cost (decisive factor for ETFs on the same index)
- Expense ratios (TER) side by side.
- Tracking difference (actual return vs index — a better cost proxy than TER; negative TD = the fund beats its own fees thanks to securities lending).
- Bid-ask spread from web data. Total cost of ownership = TER + spread × trading frequency.
- For €100k invested: annual cost in absolute € for each ETF.

### Performance and risk
- YTD / 1Y / 3Y / 5Y returns. Out/under-performance in basis points.
- Sharpe ratio if available. AUM as a liquidity proxy (prefer >€500M).
- RSI and SMA: momentum signal (not fundamentally relevant for passive ETFs).

## Output
### Comparison: {ETFs}
| Metric | {ETF1} | {ETF2} | {ETF3} | Best |
|--------|--------|--------|--------|------|
| Expense Ratio (TER) | | | | |
| Tracking Difference | | | | |
| AUM | | | | |
| YTD Return | | | | |
| 3Y Return | | | | |
| 5Y Return | | | | |
| Dividend Yield | | | | |
| Bid-Ask Spread | | | | |
| RSI (14) | | | | |

**Verdict:** Which to prefer for (1) cost-sensitive/passive investors, (2) best long-term performance, (3) income. Max 3 sentences.
If the user holds one of the ETFs: note current P&L and whether a switch is worth the transaction cost.