Filing change detector

Filing Change Detector Skill

The filing-change-detector skill automates the comparison of two chronologically consecutive regulatory filings for a given institution. By parsing share counts and pricing metrics across periods, it categorizes transactions into four distinct states: New Positions, Increased Positions, Reduced Positions, and Closed (Liquidated) Positions, highlighting capital rotation dynamics.

System Prompt Instructions

As an expert financial data engineer, you will analyze portfolio rotations using the following rigorous logic:

1. Delta Classification:
   • NEW: Security exists in the current filing ($t_0$) but not in the prior filing ($t_{-1}$).
   • INCREASED: Security exists in both filings, and share count in $t_0 >$ share count in $t_{-1}$.
   • REDUCED: Security exists in both filings, and share count in $t_0 <$ share count in $t_{-1}$.
   • CLOSED: Security exists in $t_{-1}$ but is entirely absent in $t_0$.
2. Capital Impact Computation: Calculate the estimated net transaction value for each position: $$\text{Est. Net Capital Impact} = (\text{Shares}{t_0} - \text{Shares}{t_{-1}}) \times \text{Avg. Price}_{t_0}$$ Use this metric to sort transactions by absolute capital flow size to highlight the manager's high-conviction decisions.
3. Data Currency Disclaimer: Remind the user that these shifts represent actions taken during the preceding quarter and do not reflect real-time active positioning.

Input Symbology & Schema

The skill accepts a structured JSON comparing two historical periods:

{
  "institution_name": "string",
  "prior_period": "YYYY-MM-DD",
  "current_period": "YYYY-MM-DD",
  "prior_holdings": [
    {
      "ticker": "string",
      "shares": "integer",
      "value_usd": "float"
    }
  ],
  "current_holdings": [
    {
      "ticker": "string",
      "shares": "integer",
      "value_usd": "float"
    }
  ]
}

Output Structure

The output must be formatted in a clean, highly readable layout featuring:

1. Portfolio Rotation Dashboard: Highlight metrics including total additions, complete liquidations, and net capital flow.
2. Transaction Details: Visual tables group by action (New, Closed, Increased, Reduced) listing share delta, percentage change, and estimated capital flow.

Practical Example & Real-World Output

System Execution for "Pershing Square Capital Management"

Input:

{
  "institution_name": "Pershing Square Capital Management",
  "prior_period": "2024-06-30",
  "current_period": "2024-09-30",
  "prior_holdings": [
    {"ticker": "CMG", "shares": 10000000, "value_usd": 500000000},
    {"ticker": "HLT", "shares": 15000000, "value_usd": 3000000000},
    {"ticker": "GOOGL", "shares": 8000000, "value_usd": 1200000000}
  ],
  "current_holdings": [
    {"ticker": "CMG", "shares": 8000000, "value_usd": 400000000},
    {"ticker": "HLT", "shares": 15500000, "value_usd": 3100000000},
    {"ticker": "NKE", "shares": 3000000, "value_usd": 240000000}
  ]
}

Output:

[!NOTE] Regulatory Disclosure Notice: The transaction deltas illustrated below reflect portfolio changes made during the quarter ending September 30, 2024. They are retroactive indicators of past asset rotation.

1. Portfolio Rotation Dashboard

• Total Portfolio Value (Prior Period): $4,700.00 Million
• Total Portfolio Value (Current Period): $3,740.00 Million (Note: Excludes non-disclosed holdings/cash adjustments).
• Core Activity Summary: 1 New Position established, 1 position closed/absent, 1 position increased, and 1 position reduced.

2. Rotations Classified by Strategic Action

A. established Positions (NEW)

Ticker	Asset Name	Shares Acquired	Current Value (USD Millions)	Portfolio Target Weight
NKE	Nike Inc.	+3,000,000	$240.00	$6.42%$

B. Liquidated Positions (CLOSED)

Ticker	Asset Name	Shares Closed	Prior Value (USD Millions)	Prior Portfolio Weight
GOOGL	Alphabet Inc.	-8,000,000	$1,200.00	$25.53%$

C. Increased Positions (ADDITIONS)

Ticker	Asset Name	Share Delta	Share Change (%)	Est. Capital Flow (USD Millions)
HLT	Hilton Worldwide Holdings	+500,000	$+3.33%$	+$100.00

D. Reduced Positions (DIVESTMENTS)

Ticker	Asset Name	Share Delta	Share Change (%)	Est. Capital Flow (USD Millions)
CMG	Chipotle Mexican Grill	-2,000,000	$-20.00%$	-$100.00