Current literature shows that short sellers earn positive returns on their trades and that the superior performance of short sellers is due to their better analytic skills. In this paper, we investigate, if it is poss...Current literature shows that short sellers earn positive returns on their trades and that the superior performance of short sellers is due to their better analytic skills. In this paper, we investigate, if it is possible for a short seller to make profits even if he does not have insider information or is not sophisticated. We use a one period model and assume that stock price follows a random walk with a positive drift to show that the' expected return for an uninformed short seller is always negative and his risks are always greater than the risks of a stock buyer. Hence a short seller would not trade unless he has superior trading skills and/or information. We also show that the market conditions when the stock's dividend yield is greater than the risk free rate gives the shortsellers advantage over stock buyers.展开更多
文章基于深度学习方法,通过结合粒子群优化(Particle Swarm Optimization,PSO)和长短期记忆(Long Short Term Memory,LSTM)网络,提出了一种针对大数据的商品销售预测模型。文章首先分析了LSTM的结构,其次分析了PSO方法对LSTM的优化方式...文章基于深度学习方法,通过结合粒子群优化(Particle Swarm Optimization,PSO)和长短期记忆(Long Short Term Memory,LSTM)网络,提出了一种针对大数据的商品销售预测模型。文章首先分析了LSTM的结构,其次分析了PSO方法对LSTM的优化方式,提出了PSO-LSTM商品销量预测模型,最后使用Kaggle上的数据集进行训练和测试。将所提出的模型与标准LSTM模型进行比较,结果表明,所提方法的预测精度和稳定性均优于标准LSTM方法。展开更多
文摘Current literature shows that short sellers earn positive returns on their trades and that the superior performance of short sellers is due to their better analytic skills. In this paper, we investigate, if it is possible for a short seller to make profits even if he does not have insider information or is not sophisticated. We use a one period model and assume that stock price follows a random walk with a positive drift to show that the' expected return for an uninformed short seller is always negative and his risks are always greater than the risks of a stock buyer. Hence a short seller would not trade unless he has superior trading skills and/or information. We also show that the market conditions when the stock's dividend yield is greater than the risk free rate gives the shortsellers advantage over stock buyers.
文摘文章基于深度学习方法,通过结合粒子群优化(Particle Swarm Optimization,PSO)和长短期记忆(Long Short Term Memory,LSTM)网络,提出了一种针对大数据的商品销售预测模型。文章首先分析了LSTM的结构,其次分析了PSO方法对LSTM的优化方式,提出了PSO-LSTM商品销量预测模型,最后使用Kaggle上的数据集进行训练和测试。将所提出的模型与标准LSTM模型进行比较,结果表明,所提方法的预测精度和稳定性均优于标准LSTM方法。