# Research note — earnings-day volatility

**To:** Elena Vasquez  
**From:** Aurora Capital trainee (worked example)  
**Subject:** Does NVIDIA tend to move more on earnings days than Apple?

## 1. Question

Does NVIDIA show larger absolute daily moves on earnings reaction days than Apple does, relative to ordinary days?

## 2. Method

- **Data:** Yahoo Finance daily adjusted closes for NVDA and AAPL, 2024-01-02 to 2026-07-31.  
- **Metric:** mean absolute daily return.  
- **Earnings flags:** Elena’s reaction dates (day after US close announcements). All five NVDA and five AAPL dates fell inside the sample.

## 3. Results

| Ticker | Mean |abs return| on earnings days | Mean |abs return| on normal days | Earnings days found |
| --- | ---: | ---: | ---: |
| NVDA | **8.2%** | **2.2%** | 5 |
| AAPL | **1.8%** | **1.2%** | 5 |

NVIDIA’s earnings-day moves are much larger than its normal days (about **3.8×**), and also much larger than Apple’s earnings-day average (**8.2%** vs **1.8%**). Apple’s earnings bump is milder (about **1.6×** normal). Chart: `outputs/charts/module5_earnings_volatility.png`.

## 4. Limitations

Only **five** earnings days per name — one extreme NVDA print can dominate the mean. Dates are approximate reaction days, not tick-level announcement windows. The sample sits in a strong AI narrative for NVIDIA, so the gap may shrink in a quieter regime. We did not use options or implied volatility.

## 5. Recommendation

Yes — **Aurora should expect more earnings-day noise in NVIDIA than in Apple** on this evidence. Size risk and communication around NVDA prints accordingly; do not treat Apple’s quieter earnings pattern as a template for NVDA.