# HIFFI Multi-Platform Cohort Audit Report
**Audit Timestamp:** `2026-10-26 09:14:13 UTC`  
**Total Cohort Size:** `500` artists  

## 1. Multi-Platform Coverage Summary

| Platform Signal | Covered Artists | Coverage Ratio | Verification Status |
| :--- | :---: | :---: | :---: |
| **YouTube Baseline** | `500` | `100.0%` | Complete Production Anchor |
| **Spotify Telemetry** | `206` | `41.2%` | Strict NaN (No Imputed Zeroes) |
| **Instagram Audience** | `340` | `68.0%` | Strict NaN (No Imputed Zeroes) |
| **Complete 3-Platform Signals** | `176` | `35.2%` | 100% Signal Completeness (Tier 3) |
| **Partial Platform Cohort** | `324` | `64.8%` | Proportionally Re-Weighted |

## 2. Publication Eligibility Layer

- [x] **Top 10 Evidence Gate:** Strictly requires Tier 3 (3 verified platforms) -> `PASSED`
- [x] **Top 50 Evidence Gate:** Strictly requires Tier >= 2 (>= 2 verified platforms) -> `PASSED`
- [x] **Consecutive Numbering:** Published ranks strictly contiguous from 1 to 500 without gaps or duplicates.
- [x] **Raw Score Preservation:** Continuous `hiffi_xp_score` remains unchanged before and after publication filtering.

## 3. Top Rank Gainers (Lifted by Multi-Platform Momentum)

| Artist | Prod Rank | XP Rank | Rank Delta | Spotify Listeners | IG Followers |
| :--- | :---: | :---: | :---: | :---: | :---: |
| **6ix9ine** | 490.0 | 280 | **+210** | 14,426,040 | 23,000,000 |
| **Lil Baby** | 455.0 | 259 | **+196** | 31,478,424 | 23,000,000 |
| **NBA YoungBoy** | 455.0 | 311 | **+144** | N/A | 12,000,000 |
| **Trae tha Truth** | 490.0 | 356 | **+134** | N/A | 2,000,000 |
| **Mobb Deep** | 455.0 | 345 | **+110** | 7,761,594 | 345,000 |

## 4. Top Rank Fallers (Awaiting Secondary Verification)

| Artist | Prod Rank | XP Rank | Rank Delta | Spotify Listeners | IG Followers |
| :--- | :---: | :---: | :---: | :---: | :---: |
| **Roy Woods** | 14.0 | 174 | **-160** | 3,342,003 | 986,000 |
| **Token** | 53.0 | 211 | **-158** | 3,665,603 | N/A |
| **Method Man** | 25.0 | 182 | **-157** | 3,537,700 | 3,000,000 |
| **Coco Jones** | 30.0 | 180 | **-150** | 3,608,363 | 5,000,000 |
| **Russ Millions** | 12.0 | 161 | **-149** | 3,430,231 | 1,000,000 |

## 5. Governance Compliance Verification
- [x] **Zero-Imputation Policy:** Missing platform values preserved as genuine `NaN`.
- [x] **Monotonicity & Bounds:** HIFFI-XP bounded in `[0.0, 100.0]`; inverse rank monotonic.
- [x] **Proportional Dynamic Weighting:** Active platforms dynamically re-allocated.
- [x] **Test Suite Status:** 20 of 20 tests passing via `pytest test_multiplatform_ranking.py`.