Does trading by small investors improve or deteriorate price efficiency?

In this study, we investigate the effect of minimum trade unit (MTU) reductions on the Korea Exchange (KRX) on price efficiency. The KRX switched its MTU from 10 shares to one share for high-price stocks twice, once in December 2004 and once in July 2006. The MTU changes were intended to attract small individual investors to the markets for high-price stocks. The MTU reductions on the KRX are different from previous cases of MTU reductions in other markets in that the KRX MTU reductions are not chosen by firms but are mandated by the exchange. Using these rare events, we examine whether the reductions in MTU and ensuing small investor participation enhance or deteriorate price efficiency. We examine three variables as indicators of price efficiency: return volatility, residual volatility, and the half-life of return volatility shock estimated from a generalized autoregressive conditional heteroskedasticity (GARCH) model. We find evidence of improved price efficiency from the 2004 event. For the 2004 sample, both return variance and residual return variance declined significantly after the MTU reduction. We also find evidence of reduction, albeit weak, in the half-life of volatility shock for the same sample. Meanwhile, for the 2006 sample, we do not find any changes in return variance or residual variance, nor do we find any evidence of change in the half-life of volatility shock. The difference in the patterns of changes in variables between the 2004 and 2006 events appears to be attributable to differences in the price levels of the stocks that were affected by the MTU changes and, consequently, a difference in reactions by small investors

The components of the bid-ask spread in a limit-order market: Evidence from the Tokyo Stock Exchange

This paper analyzes the components of the bid-ask spread in the limit-order book of the Tokyo Stock Exchange (TSE). While the behavior of spread components in U.S. markets has been extensively studied, little is known about the spread components in a pure limit-order market. We find that both the adverse selection and order handling cost components of the TSE exhibit U-shape patterns independently, in contrast to the findings of Madhavan, Richardson, and Roomans (1997) for U.S. stocks. On the TSE, there does not exist an upstairs market that allows large trades to be prenegotiated or certified as on the New York Stock Exchange (NYSE). This feature of the TSE provides a valuable opportunity to examine the relationship between trade size and spread components. Our results show that the adverse selection cost increases with trade size while order handling cost decreases with it

Who Are Less Likely to Receive Subsequent Chemotherapy Beyond First-Line Therapy for Advanced Non-small Cell Lung Cancer?: Implications for Selection of Patients for Maintenance Therapy

BackgroundProspective studies have implied that maintenance therapy for non-small cell lung cancer (NSCLC) has its effect by giving active drugs earlier to patients who otherwise die without receiving second-line therapy. The purpose of this study was to select patients with NSCLC who could most benefit from maintenance therapy, by evaluating which patients would be less likely to receive second-line therapy.MethodsClinicopathologic data of patients with advanced NSCLC who received four cycles of first-line chemotherapy followed by time-off therapy and eventual disease progression or death were reviewed retrospectively. Patients were grouped into ones with first-line therapy only or ones with more than first-line therapy. Clinical characteristics between the two groups were compared.ResultsA total of 271 patients were eligible for analysis, and 39 patients (14.4%) received only first-line therapy. Patients significantly more likely to receive only first-line therapy had performance status of two or three after first-line therapy, large volume of initial target lesions (sum of long diameters ≥70 mm), or smaller decrease in target lesions (decrease <20%) after first-line therapy. Median overall survival of the 143 patients (52.8%) with at least one of these characteristics (16.3 months) was significantly shorter than that of patients without any of these characteristics (23.5 months, p = 0.007).ConclusionMaintenance therapy may be of greater benefit to patients with NSCLC who have clinical characteristics including poor performance status after first-line therapy, large initial target lesions, or smaller decrease in target lesions after first-line therapy

Differential profiling of breast cancer plasma proteome by isotope-coded affinity tagging method reveals biotinidase as a breast cancer biomarker

<p>Abstract</p> <p>Background</p> <p>Breast cancer is one of the leading causes of women's death worldwide. It is important to discover a reliable biomarker for the detection of breast cancer. Plasma is the most ideal source for cancer biomarker discovery since many cells cross-communicate through the secretion of soluble proteins into blood.</p> <p>Methods</p> <p>Plasma proteomes obtained from 6 breast cancer patients and 6 normal healthy women were analyzed by using the isotope-coded affinity tag (ICAT) labeling approach and tandem mass spectrometry. All the plasma samples used were depleted of highly abundant 6 plasma proteins by immune-affinity column chromatography before ICAT labeling. Several proteins showing differential abundance level were selected based on literature searches and their specificity to the commercially available antibodies, and then verified by immunoblot assays.</p> <p>Results</p> <p>A total of 155 proteins were identified and quantified by ICAT method. Among them, 33 proteins showed abundance changes by more than 1.5-fold between the plasmas of breast cancer patients and healthy women. We chose 5 proteins for the follow-up confirmation in the individual plasma samples using immunoblot assay. Four proteins, α1-acid glycoprotein 2, monocyte differentiation antigen CD14, biotinidase (BTD), and glutathione peroxidase 3, showed similar abundance ratio to ICAT result. Using a blind set of plasmas obtained from 21 breast cancer patients and 21 normal healthy controls, we confirmed that BTD was significantly down-regulated in breast cancer plasma (Wilcoxon rank-sum test, <it>p </it>= 0.002). BTD levels were lowered in all cancer grades (I-IV) except cancer grade zero. The area under the receiver operating characteristic curve of BTD was 0.78. Estrogen receptor status (<it>p </it>= 0.940) and progesterone receptor status (<it>p </it>= 0.440) were not associated with the plasma BTD levels.</p> <p>Conclusions</p> <p>Our study suggests that BTD is a potential serological biomarker for the detection of breast cancer.</p

A Case of Disseminated and Fulminant Plasmacytomas That Developed during Bortezomib Treatment

Multiple myeloma is an incurable and slow growing plasma cell neoplasm. The introduction of new drugs has increased the number of treatment options. Bortezomib, the first-in-class proteasome inhibitor, has been shown to have a significant antitumor activity in the treatment of relapse/refractory patients with multiple myeloma. Additionally, plasmacytomas have shown significant response to bortezomib. In this case report, we describe a patient who developed disseminated and fulminant extramedullary plasmacytomas during combination chemotherapy treatment with bortezomib within a short period, after having shown clinical improvement