NFLX news volume vs sentiment as next-day absolute return predictor
Netflix makes its biggest moves the day after the news volume spikes — not the day after coverage turns strongly positive or negative. Over the past three years, the top-decile news-volume days saw average absolute returns 44% bigger than the norm, while top-decile sentiment days were a statistical coin flip.
The contrast is clean: raw attention, measured by article count, signals a coming swing; the emotional tone of that coverage does not. Below, you’ll find the full breakdown — the numbers, the charts, and the logic behind why media buzz, not narrative, is the real volatility precursor for NFLX.
For NFLX over the past ~3 years, do days with top-decile news article volume predict larger absolute next-day returns than days with top-decile sentiment, indicating that raw attention, not the narrative tone, foreshadows big moves? Thesis: Media buzz cranks up before the stock swings, so coverage volume beats sentiment as a volatility precursor.
How this was measured
Daily NFLX close-to-close absolute returns, shifted one day forward, joined with same-day news article count (volume) and mean absolute sentiment (|ticker_sentiment_score|, fallback |overall_sentiment_score|). Top decile thresholds (above 90th percentile) define high-volume and high-sentiment days. Next-day absolute return means compared across three slices: baseline (all days), top-decile volume, top-decile sentiment, plus mutually exclusive pure groups (volume-top-only and sentiment-top-only). Welch t-tests assess whether each predictor signals larger next-day swings; exclusive-group test addresses overlap. Look-ahead: next-day |return| uses close[t+1]/close[t]-1, so no future leakage.
The key numbers
Reading the numbers
Over 446 trading days, days with top-decile news volume saw an average next-day absolute return of 2.22% versus 1.54% on all days (p=0.03), while top-decile sentiment days averaged just 1.48% (p=0.77). This means heavy media coverage, not the tone of coverage, tends to precede bigger stock moves.
The charts
This histogram shows the distribution of next-day absolute returns across all 446 trading days. The average daily move is 1.54%, with most returns clustered below 5% and a long tail reaching up to 15.5%. It sets the baseline for comparing the other conditions.
On the 47 days with the highest news volume (22+ articles), the average next-day absolute return jumps to 2.22%, nearly 50% higher than the baseline. The distribution also shows a fatter tail, with several days exceeding 5% and one approaching 10.6%. This indicates that intense media attention often precedes larger-than-normal stock swings.
For the 45 days with extreme sentiment scores (either very positive or very negative), the average next-day absolute return is 1.48% — essentially the same as the baseline 1.54%. The distribution is even more compact, with no days above 6%. Unlike high volume, strong sentiment alone does not foreshadow outsized moves.
This side-by-side box plot puts the three conditions in direct comparison. The 'Top volume' group clearly has a higher median and a wider spread, with the box extending into the 3-4% range. In contrast, 'Top sentiment' mirrors 'All days' almost exactly. The visual evidence is consistent with the statistical tests: only high article volume, not extreme sentiment, signals elevated next-day volatility.
Group summary statistics
| Group | N | Mean |return| | Std |
|---|---|---|---|
| All days | 446 | 0.0154 | 0.0164 |
| Top Volume (≥90%) | 47 | 0.0221 | 0.0201 |
| Top Sentiment (≥90%) | 45 | 0.0148 | 0.013 |
| Pure Volume (excl.) | 46 | 0.0225 | 0.0202 |
| Pure Sentiment (excl.) | 44 | 0.015 | 0.013 |
The takeaway
Yes, days with top-decile news volume do predict notably larger next-day NFLX price swings, while extreme sentiment days don't budge the needle. On high-volume days the average absolute return was 2.21%, versus a 1.54% baseline — about 44% bigger. The pure-volume group (days that were high in volume but not in sentiment) averaged 2.25%, compared to just 1.50% for pure-sentiment days. The difference is statistically significant: there's only about a 3-in-100 chance it's random noise for volume versus baseline, and a similar 4-in-100 chance for the pure-volume vs. pure-sentiment comparison (p = 0.038). By contrast, top-decile sentiment alone produced a mean return of 1.48%, which is basically indistinguishable from the baseline (p = 0.77) — a coin flip. So raw attention, not the emotional tone of coverage, is the meaningful precursor to bigger NFLX volatility. The samples are modest (roughly 45 days per group), so the result is a solid signal rather than a slam dunk, but it squarely supports the thesis that media buzz cranks up before the stock moves.
The fine print
- Top-decile thresholds are defined using in-sample data; out-of-sample performance may differ.
- Each extreme group contains only 44–47 trading days, limiting precision and statistical power.
- Daily sentiment is averaged across all headlines, which could mute the impact of strongly mixed coverage on a given day.
- Volume is a raw article count, not weighted by relevance or source credibility, so noisy headlines may dilute the signal.