-post and ex-ante types), of cancellation fees and of transaction taxes on asset price volatility and on the occurrence and …, the introduction of an ex-ante circuit breaker markedly reduces price volatility and removes flash crashes. In contrast … price fluctuations. In addition, high-frequency traders employ low-latency directional strategies that exploit market …

International financial markets are said to be excessively volatile due to destabilizing speculation and excessive … liquidity, which minimizes excess volatility. There are two effects when imposing a transactions tax. Both reduce excess … volatility in highly speculative markets when tax rates are small. The total tax effect then is unambiguous. However, in illiquid …

increase in price volatility as well, however, under certain conditions. Price changes from pyramiding effect are also … reduction in the margin requirement may cause the stock price to rise in the current period because it increases the demand of … negatively associated with margin requirements. Price changes from depyramiding effect, however, may not be affected when margin …

funds and swap dealers cause price changes or volatility. We find little evidence that speculators destabilize financial … markets. To the contrary, speculative trading activity largely reacts to market conditions and reduces volatility levels …

investors present (i) price deviations from fundamentals are larger; (ii) prices are more volatile; (iii) mispricing increases …

find that in markets with only speculating investors (i) price deviations from fundamentals are larger; (ii) prices are …