使用原書 Table 6.6–6.7 建立 Amazon 2021E–2025E Stockholders’ Equity projection，重點放在 AOCI 與 Retained Earnings 的 roll-forward。
Preferred Stock、Common Stock + APIC 與 Treasury Stock 在本階段沿用 prior balance；AOCI 由 Foreign Currency Effect 推動。原書假設 Stock-Based Compensation 尚未 vested，因此先透過 Retained Earnings roll-forward 處理，並提醒 vesting 時對 Common Stock + APIC 的處理可能不同。
| Equity account | 2020A | Projection driver |
|---|---|---|
| Preferred Stock | 0 | Flat-line |
| Common Stock + APIC | 42,870 | 本階段 flat-line |
| Treasury Stock | (1,837) | 本階段 flat-line |
| AOCI | (180) | Foreign Currency Effect |
| Retained Earnings | 52,551 | Net Income + Stock-Based Compensation |
AOCI(t) = AOCI(t−1) + FX Effect(t)。Retained Earnings(t) = Retained Earnings(t−1) + Net Income(t) + Stock-Based Compensation(t)，依原書本章假設。Total Equity 為各 equity accounts 加總。
| US millions | 2021E | 2022E | 2023E | 2024E | 2025E |
|---|---|---|---|---|---|
| AOCI | (531) | (461) | 157 | (194) | (124) |
| Retained Earnings | 89,769.3 | 132,764.4 | 178,211.3 | 224,086.7 | 267,568.0 |
| Total Stockholders’ Equity | 130,271.3 | 173,336.4 | 219,401.3 | 264,925.7 | 308,477.0 |
2021E Retained Earnings 驗算：52,551 + 25,524.1 Net Income + 11,694.2 SBC = 89,769.3。
Equity projection 必須區分真正沒有預測變動的 accounts 與由 earnings／currency effects 推動的 accounts。Retained Earnings 是三表模型的重要橋樑；若 Net Income 改變但 equity 未同步 roll-forward，Balance Sheet 會失衡。
請只根據 Table 6.6–6.7，重算 2021E Retained Earnings 89,769.3，並解釋 AOCI 與 Retained Earnings 各自由哪些 Cash Flow／P&L drivers 推動。