Two Essays on Short Selling

This dissertation provides some new evidence that the information contained in short selling is informative about future returns, confirming the role of short sellers in the price discovery process. The first essay examines the cross-sectional relation between the change in short interest and expected stock returns. NYSE/AMEX stocks with large decreases (increases) in short interest over past medium-term horizon experience significant and positive (negative) abnormal returns. Moreover, the positive abnormal returns are larger in absolute value and are more persistent than negative abnormal returns. The return spread between bottom and top deciles is economically and statistically significant and persistent. The return predictability of the change in short interest is not subsumed by the level of short interest and other well-known determinants of stock returns, and is robust in different calendar months and investor sentiment. These results imply that public information contained in the change in short interest is so slowly incorporated into prices. Moreover, the asymmetry in the speed of price adjustment casts doubts on the implication of short-sale constraints and the limits to arbitrage. The second essay provides new evidence that momentum and long-term reversals would be separate phenomena. We can identify ex ante momentum stocks that exhibit persistent momentum and those that exhibit weak momentum but persistent reversals, using information in short selling. Underreaction and overreaction theories apply to different sets of momentum stocks. The consistent momentum strategy based on short interest succeeds during periods in which the standard momentum strategy fails. The success of the consistent momentum strategy is mainly due to the robust return predictability of short interest in these periods. These evidence confirms that short sellers contribute to price discovery. The information in short selling provides a great hedge or complement to anomaly-based strategies

Transcriptome-wide high-throughput deep m6A-seq reveals unique differential m6A methylation patterns between three organs in Arabidopsis thaliana

Proportion of two types of m6A distributing feature in mRNA. (DOC 30 kb

Musca domestica Cecropin (Mdc) Alleviates Salmonella typhimurium-Induced Colonic Mucosal Barrier Impairment: Associating With Inflammatory and Oxidative Stress Response, Tight Junction as Well as Intestinal Flora

Salmonella typhimurium, a Gram-negative food-borne pathogen, induces impairment in intestinal mucosal barrier function frequently. The injury is related to many factors such as inflammation, oxidative stress, tight junctions and flora changes in the host intestine. Musca domestica cecropin (Mdc), a novel antimicrobial peptide containing 40 amino acids, has potential antibacterial, anti-inflammatory, and immunological functions. It remains unclear exactly whether and how Mdc reduces colonic mucosal barrier damage caused by S. typhimurium. Twenty four 6-week-old male mice were divided into four groups: normal group, control group (S. typhimurium-challenged), Mdc group, and ceftriaxone sodium group (Cs group). HE staining and transmission electron microscopy (TEM) were performed to observe the morphology of the colon tissues. Bacterial load of S. typhimurium in colon, liver and spleen were determined by bacterial plate counting. Inflammatory factors were detected by enzyme linked immunosorbent assay (ELISA). Oxidative stress levels in the colon tissues were also analyzed. Immunofluorescence analysis, RT-PCR, and Western blot were carried out to examine the levels of tight junction and inflammatory proteins. The intestinal microbiota composition was assessed via 16s rDNA sequencing. We successfully built and evaluated an S. typhimurium-infection model in mice. Morphology and microcosmic change of the colon tissues confirmed the protective qualities of Mdc. Mdc could inhibit colonic inflammation and oxidative stress. Tight junctions were improved significantly after Mdc administration. Interestingly, Mdc ameliorated intestinal flora imbalance, which may be related to the improvement of tight junction. Our results shed a new light on protective effects and mechanism of the antimicrobial peptide Mdc on colonic mucosal barrier damage caused by S. typhimurium infection. Mdc is expected to be an important candidate for S. typhimurium infection treatment

Subsequent monitoring of ferric ion and ascorbic acid using graphdiyne quantum dots-based optical sensors

Graphdiyne (GDY) as an emerging carbon nanomaterial has attracted increasing attention because of its uniformly distributed pores, highly π-conjugated, and tunable electronic properties. These excellent characteristics have been widely explored in the fields of energy storage and catalysts, yet there is no report on the development of sensors based on the outstanding optical property of GDY. In this paper, a new sensing mechanism is reported built upon the synergistic effect between inner filter effect and photoinduced electron transfer. We constructed a novel nanosensor based upon the newly-synthesized nanomaterial and demonstrated a sensitive and selective detection for both Fe3+ ion and ascorbic acid, enabling the measurements in real clinical samples. For the first time fluorescent graphdiyne oxide quantum dots (GDYO-QDs) were prepared using a facile ultrasonic protocol and they were characterized with a range of techniques, showing a strong blue-green emission with 14.6% quantum yield. The emission is quenched efficiently by Fe3+ and recovered by ascorbic acid (AA). We have fabricated an off/on fluorescent nanosensors based on this unique property. The nanosensors are able to detect Fe3+ as low as 95 nmol L−1 with a promising dynamic range from 0.25 to 200 μmol L−1. The LOD of AA was 2.5 μmol L−1, with range of 10–500 μmol L−1. It showed a promising capability to detect Fe3+ and AA in serum samples

Fundamental Strength and the 52-Week High Anchoring Effect

International audienceWhen stocks are trading near their 52-week high investors tend to have low expectation about their future returns. We contrast such expectations against firms' fundamental strength. For firms with strong fundamentals, we confirm that investors' expectations are too low, which is consistent with the hypothesis that the 52-week high acts as a psychological anchor. We report that a fundamental-strength enhanced 52-week high trading strategy significantly outperform the unconditional strategy by nearly doubling its average return. Moreover, we provide interesting evidence that this anomalous effect is most evident when investor sentiment is high, but absent among more sophisticated institutions and short sellers

Herding towards carbon neutrality: The role of investor attention

International audienceThis paper explores the herding towards carbon neutrality in the Chinese stock market. We find that herding towards carbon neutrality does dynamically exist in the Chinese stock market. Specifically, herding is pronounced during the bear markets and market stress periods such as the post-COVID-19 period. There is a size effect for the herding behavior. Investor attention could significantly decrease the magnitude of herding. Our results hold in various robustness tests. This paper provides some important implications on the style investing, fads, and carbon neutrality