/etf-cost

Cosa fa. Stima il costo reale di un ETF, oltre al solo TER.

Quando usarlo. Per sapere quanto ti costa davvero detenerlo.

Argomenti. ETF

Esempio. /etf-cost SWDA.MI

Cosa restituisce. TER, tracking difference, spread, tax drag e costo complessivo.

Come funziona

Quando lanci /etf-cost, 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_all_etfs, get_stock_price, web_search, web_fetch.

Prompt completa

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

Full real-cost analysis for {arg}.
Guard: if "{arg}" is empty or literally "{arg}", respond: "Usage: /etf-cost VWCE" and stop.

## Step 1 — Data (parallel)
- get_etf_profile → expense ratio, AUM, category, fund family, YTD/3Y/5Y returns
- get_all_etfs → peers in the same category to benchmark the expense ratio
- get_stock_price → current price (spread context)

web_search: "{arg} tracking difference total cost ownership bid-ask spread site:justetf.com OR site:trackingdifferences.com OR site:etf.com"
web_fetch the top result. Extract: tracking difference (1Y, 3Y), bid-ask spread, average daily volume, replication method.

## Step 2 — Cost components

### 1. Expense Ratio (TER)
- Stated annual management fee. Category average from get_all_etfs peers.
- For €10k / €50k / €100k invested: annual cost in absolute €.

### 2. Tracking Difference (TD)
- Fund's actual return vs index (a better cost proxy than TER).
- If TD < TER: the fund generates alpha via securities lending → effectively cheaper than stated.
- If TD > TER: additional costs (rebalancing, FX, taxes on underlying dividends) erode returns.
- Reference: prefer ETFs with TD < 0.10% for developed-market large-cap indices.

### 3. Bid-Ask Spread
- Spread from web data. Cost paid on EVERY buy/sell.
- Annual drag if rebalancing quarterly = spread × 4 × 0.5 (round-trip / 2 per leg).
- AUM >€1B and average daily volume >€10M = liquid (low spread). AUM <€100M = illiquidity risk.

### 4. Tax Drag
- Accumulating (UCITS IE-domiciled): WHT on dividends avoided for most EU investors → preferable.
- Distributing: dividends paid out → taxed as income in the investor's country.
- US-domiciled ETF: 15% WHT on dividends (vs 0% with UCITS) → significant drag for EU investors with high-yield ETFs.
- Synthetic replication: avoids WHT on the underlying stocks' dividends → lower tax drag, but counterparty risk.

### 5. FX hedging cost (if applicable)
- Currency-hedged ETF: hedging cost ~0.3-0.7% p.a. for EUR/USD, varies with the rate differential.
- Justified only for short horizons; unhedged FX exposure may be preferable long-term for diversification.

## Output
### {arg} — Total Cost of Ownership
| Cost component | % per year | €/year on €100k | Note |
|----------------|-----------|------------------|------|
| TER (stated) | | | |
| Tracking Difference | | | |
| Bid-Ask Spread (estimate) | | | |
| Tax Drag | | | |
| FX Hedging (if present) | | | |
| **Estimated total** | | | |

**vs category average:** {arg} is [X bps] cheaper / more expensive than average.
**Tracking difference verdict:** [Better than TER / In line / Worse than TER] — [reason + any securities lending]
**Cheaper alternatives in the same category:** [1-2 tickers from get_all_etfs with lower TD/TER]

**Cost rating:** ⭐⭐⭐ (TER <0.10%, TD <0.05%) / ⭐⭐ (TER 0.10–0.30%) / ⭐ (TER >0.30%)