Among the important characteristics of market efficiency is (are) that:
i. there are no arbitrage opportunities.
ii. security prices react quickly to new information.
iii. active trading strategies will consistently outperform passive strategies.

I, II, and III.

Explanation:

Market efficiency demonstrates that prices mirror the entire information regarding a specific market or stock which is accessible at a given point of time. There are certain important characteristics of an efficient market which include a number of participants, uniformity in products, etc. As per the options, all the three options could be characterized as the important characteristics of market efficiency which are as follows:

I). 'There are no arbitrage opportunities' as there is complete awareness among the consumers regarding the availability of products and its prices.

II). 'Security prices react quickly to new information' as there is a consensus value of a product set by all the customers and sellers after assessing its value.

III). 'Active trading strategies will consistently outperform passive strategies' as there is perfect competition and therefore, there is a liberty to enter and exit the market at any point in time.

answer; (trauma);

answer; caravan;