Say, Echo, Do: Strategic Narratives and Revealed Positioning in Financial Markets
Organizations: Riyadh, Saudi Arabia
Abstract
Machine-learning signals built from financial text treat what institutions say, and what the media repeat, as evidence about value. But whoever shapes a narrative may be trading against it. We study markets with three observable voices: institutional statements (Say), media repetition (Echo) and revealed positioning (Do). We ask when words should be followed and when they should be faded. In a linear-quadratic model of an informed institution that speaks and trades before a partly credulous crowd, talking an asset down while buying it is optimal exactly when . A distribution-free identity then shows that when the observable Say-Do covariance is negative, words carry negative predictive content and should be faded. For measurement, we derive (i) an exact factorised posterior over which articles are echoes, combining arrival times with embedding similarity; (ii) a return-aligned contrastive objective that attains its bound exactly when squared embedding distances are an increasing affine function of squared outcome distances, with the tightest loss-based certificate of which neighbour rankings survive imperfect training; and (iii) a path-signature statistic for who moved first. In a controlled market with known ground truth, echo sentiment predicts returns with a significantly negative sign in all 29 simulated markets, the rolling Say-Do correlation flags false-alarm events with an AUC of 0.90, and return-aligned embeddings organise headlines by consequence rather than topic. We also report where the tools fail.
Figures & tables
| Regressor | Source | Prediction | As predicted | |
|---|---|---|---|---|
| Echo sentiment | Corollary 2 | (fade) | 5/5 | |
| News sentiment | Corollary 2 | (follow) | 3/5 | |
| Say, where rolling | Theorem 4 | (fade) | 4/5 | |
| Absorption, institution trades | Theorem 14 | either | – | |
| Absorption, institution does not trade | Theorem 14 | 4/5 | ||
| Signed Lévy area | Theorem 9 | 1/5 |
| Variant | IC | echo | news | AUC | echo share |
|---|---|---|---|---|---|
| Reference | ( ) | ||||
| Fat-tailed values ( ) | ( ) | ||||
| Saturating crowd | ( ) | ||||
| Power-law echo delays | ( ) | ||||
| 30% of trade disclosed, noisier | ( ) | ||||
| Weak meaning ( ) | ( ) |
Appendix figures & tables17 assets
Supplementary material from the paper’s appendix.
Appendix
| Result | Quantity | Theory | Check |
|---|---|---|---|
| Three-voice economy ( Section 3.1 ) | |||
| Corollary 2 | Bayes weight on the echo channel | ||
| Theorem 1 | return loading on the echo channel | ||
| Theorem 13 | loading on positioning, | ||
| Theorem 14 | absorption coefficient, | ||
| Strategic speech ( Section 3.2 ) | |||
| Feature | Construction | Source |
|---|---|---|
| News, echo | over articles other than the statement; | Propositions 24 and 6 |
| Say–Do switch | correlation of Say and Do over the firm’s previous events; words are faded when it is below | Theorem 4 |
| Absorption | price reaction minus the narrative-implied move, fitted linearly on Say, and (pooled, or per firm; tone is their sum) | Theorem 14 |
| Lead–lag | Lévy area of (positioning, tone) over the event window, signed by the direction of the positioning change | Theorem 9 |
| Composite | unit weights on the standardised terms above, with the switch applied to Say | Section 4.4 |
| Regressor (controls) | Prediction | Coef. | As predicted | |
|---|---|---|---|---|
| News sentiment (Say, Do) | ( Corollary 2 ) | 3/5 | ||
| Echo sentiment (Say, Do) | ( Corollary 2 ) | 5/5 | ||
| Say, fade group (Do) | ( Theorem 4 ) | 4/5 | ||
| Say, fade group (Do, news, echo) | 1/5 | |||
| Say, follow group (Do, news, echo) | either | – | ||
| Do (Say by group, news, echo) | 1/5 |
| IC | -statistic | |||||||
|---|---|---|---|---|---|---|---|---|
| Variant | fade price | linear | + theory | echo | news | Lévy | AUC | echo share |
| Reference | ( ) | |||||||
| Fat tails ( values) | ( ) | |||||||
| Saturating crowd | ( ) | |||||||
| Power-law echo delays | ( ) | |||||||
| 30% of trade disclosed | ( ) | |||||||
| Method | Week-ahead IC | Same consequence | Same topic |
|---|---|---|---|
| TF-IDF neighbours (generic) | |||
| Random 16-d projection (generic) | |||
| Ridge regression on words (supervised) | – | – | |
| Gradient boosting on words (supervised) | – | – | |
| Return-aligned embedding, 16-d |