longbridge-etf-analysis

Original：🇺🇸 English

Translated

ETF analysis framework via Longbridge — product screening (AUM/expense ratio/index), tracking error, liquidity (bid-ask spread/volume), premium/discount (NAV vs market price), and A-share ETF allocation insights. Triggers: "ETF分析", "ETF选择", "ETF跟踪误差", "ETF溢价", "ETF流动性", "ETF费率", "ETF规模", "宽基ETF", "行业ETF", "指数基金", "ETF分析", "ETF選擇", "ETF追蹤誤差", "ETF溢價", "ETF流動性", "ETF費率", "ETF規模", "指數基金", "ETF analysis", "ETF selection", "tracking error", "ETF premium discount", "ETF liquidity", "expense ratio", "broad market ETF", "sector ETF", "index fund".

3installs

Sourcelongbridge/skills

Added on2026-05-13

NPX Install

npx skill4agent add longbridge/skills longbridge-etf-analysis

SKILL.md Content

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longbridge-etf-analysis

Prompt-only analysis skill. Analyses ETFs across five dimensions: product profile, tracking error, liquidity, premium/discount, and allocation fit — supporting both US-listed ETFs and A-share ETFs.

Response language: match the user's input language — Simplified Chinese / Traditional Chinese / English.

When to use

"QQQ 和 QQQM 哪个更适合长期持有？" / "QQQ vs QQQM for long-term holding?"
"这只 ETF 的跟踪误差大不大？" / "Is the tracking error on this ETF high?"
"510300 现在溢价还是折价？" / "Is 510300 trading at a premium or discount?"
"帮我分析沪深300 ETF 的流动性" / "Analyse the liquidity of CSI 300 ETFs"
"行业 ETF 怎么选？" / "How to pick a sector ETF?"

For index constituent stocks route to

longbridge-constituent

. For individual stock valuation route to

longbridge-valuation

.

CLI

Run

longbridge <subcommand> --help

to verify exact flags.

bash

# ETF quote — price, volume, market cap, turnover
longbridge quote <ETF_SYMBOL> --format json

# Constituent holdings — underlying stocks and weights
longbridge constituent <ETF_SYMBOL> --format json

# Historical price — compute tracking error vs index
longbridge kline <ETF_SYMBOL> --period day --count 60 --format json

# Index / benchmark price for comparison
longbridge kline <BENCHMARK_SYMBOL> --period day --count 60 --format json

# Valuation indices (PE/PB of ETF if available)
longbridge calc-index <ETF_SYMBOL> --format json

Five-dimension analysis

1. Product profile

Extract from

quote

+

constituent

output:

Underlying index tracked
AUM / total market cap (proxy)
Expense ratio (if available in quote metadata; otherwise note "check fund prospectus")
Inception date / listing exchange

2. Tracking error

Fetch ETF daily kline and benchmark daily kline (60 bars).
Daily return difference:
```
d_i = r_ETF_i − r_index_i
```
Tracking error (annualised):
```
TE = std(d) × √252
```
Interpretation: TE < 0.3% excellent; 0.3–1% acceptable; > 1% investigate.

3. Liquidity

From

quote

:

Average daily volume and turnover
Bid-ask spread (if tick data available; otherwise use turnover-rate as proxy)
Liquidity flag: turnover-rate > 0.5% = liquid; < 0.1% = illiquid (A-share ETFs)

4. Premium / discount (NAV vs market price)

For A-share ETFs:

premium = (market price − NAV) / NAV × 100%

NAV may not be in real-time quote; note this and use EOD NAV if available.
Persistent premium > 2% or discount < −2% signals arbitrage opportunity or liquidity issue.
For US ETFs: premium/discount is typically < 0.1% due to continuous creation/redemption.

5. Allocation fit

Index type: broad market (SPY/QQQ/510300) vs sector (XLK/515790) vs factor (value/growth/momentum)
Currency and market exposure
Overlap analysis: if user holds multiple ETFs, flag significant holdings overlap from
```
constituent
```

Workflow

Resolve ETF symbol to
```
<CODE>.<MARKET>
```
(e.g.
```
SPY.US
```
,
```
510300.SH
```
).
Concurrently fetch:
```
quote
```
,
```
constituent
```
, ETF kline, benchmark kline.
Compute TE, assess liquidity, estimate premium/discount.
Summarise all five dimensions.
Output structured report (template below). Cite Longbridge Securities.

Output template

{ETF Symbol} analysis — Source: Longbridge Securities

[1. Product profile]
- Index tracked: {name}  |  Exchange: {ex}
- AUM proxy (mkt cap): {$X}  |  Expense ratio: {X% / see prospectus}

[2. Tracking error (60-day)]
- Annualised TE: X%  → {excellent / acceptable / elevated}

[3. Liquidity]
- Avg daily volume: {X}  |  Turnover rate: X%  → {liquid / moderate / illiquid}
- Bid-ask spread estimate: {X% / data unavailable}

[4. Premium / Discount]
- Latest: {+X% premium / −X% discount / ~flat}
- Note: {A-share ETF — NAV published after close / US ETF — near-zero typical}

[5. Allocation fit]
- Type: {broad market / sector / factor}
- Key holdings (top 5): {list from constituent}
- Currency exposure: {USD / CNY / HKD}

[Summary]
{2–3 sentence overall assessment}

⚠️ 以上分析仅供参考，不构成投资建议。/ 以上分析僅供參考，不構成投資建議。/ For reference only. Not investment advice.

Error handling

Situation	简体回复	繁體回復	English reply
`command not found: longbridge`	切换到 MCP；若不可用，请安装 longbridge-terminal	切換至 MCP；若不可用，請安裝 longbridge-terminal	Fall back to MCP; if unavailable, install longbridge-terminal
stderr `not logged in`	请执行 `longbridge auth login`	請執行 `longbridge auth login`	Run `longbridge auth login`
`constituent` returns empty	持仓数据暂不可用，跳过重叠分析	持倉數據暫不可用，跳過重疊分析	Constituent data unavailable; skipping overlap analysis
Benchmark kline unavailable	无法计算跟踪误差，仅显示 ETF 本身收益	無法計算追蹤誤差，僅顯示 ETF 本身收益	Cannot compute TE; showing ETF return only

MCP fallback

CLI command	MCP tool
`longbridge quote`	`mcp__longbridge__quote`
`longbridge constituent`	`mcp__longbridge__constituent`
`longbridge kline`	`mcp__longbridge__candlesticks`
`longbridge calc-index`	`mcp__longbridge__calc_indexes`

Related skills

Constituent stock list →
```
longbridge-constituent
```
Individual stock valuation →
```
longbridge-valuation
```
Capital flow into ETF holdings →
```
longbridge-capital-flow
```
Market / index temperature →
```
longbridge-market-temp
```

File layout

longbridge-etf-analysis/
└── SKILL.md          # prompt-only, no scripts/

longbridge-etf-analysis

NPX Install

Tags

SKILL.md Content

longbridge-etf-analysis

When to use

CLI

Five-dimension analysis

1. Product profile

2. Tracking error

3. Liquidity

4. Premium / discount (NAV vs market price)

5. Allocation fit

Workflow

Output template

Error handling

MCP fallback

Related skills

File layout