The expansion of investment arbitration has resulted in concern that unmeritorious claims be dealt with in a prompt, effective fashion. This is reflected for example in the 2006 amendment to the ICSID Rules. Arbitral institutions cannot generally exclude unmeritorious claims. They must be dealt with by Tribunals themselves. Tribunals have the possibility of dealing with these issues at the outset by bifurcation. Although the results of the 2006 ICSID amendments are disappointing, the recent cases show a tendency to deal critically with the effect of fraud on jurisdiction in investment arbitration. However, the main sanction for unmeritorious claims is an award of costs. Based on empirical analysis, the current trend is that costs follow the event in investment arbitration as it has in international commercial arbitration. This raises an issue as to whether and in what conditions security for costs should be ordered.