"They Say So": Do True, False, Negative, and Positive Rumours Affect Stock Price in Different Ways?
Bibliographic record
Abstract
<p>In this thesis I examine the effect of rumours on stock prices by the means of event study methodology. The evidence offered by previous studies on the effect of rumours on stock prices and returns is mixed, thus the topic merits further investigation. One distinguishing characteristic of this study is that it examines different types of rumours (positive versus negative), as well as whether these rumours are true or false. Using a dataset that includes the rumours on 110 stocks and applying the event study methodology, I find no evidence of statistically significant changes in stock prices after the publication of rumours. Furthermore, I find that the type of rumours, whether positive or negative, and its nature, whether false or true, did not affect the observed results in terms of statistical significance. </p>
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.012 | 0.029 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.002 | 0.005 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".