Firstly, it is important to note that the EMH has three forms: weak, semi-strong, and strong. The weak form suggests that prices reflect all past trading information, the semi-strong form suggests that prices reflect all publicly available information, and the strong form suggests that prices reflect all information, including private information that is not publicly available. Empirical studies have tested the efficiency of the LSE under different forms of the EMH. For example, a study by Clare et al. (1998) tested the weak-form efficiency of the LSE using daily data from 1980 to 1994. The authors found that the LSE was weak-form efficient, which implies that past trading information is already reflected in stock prices.

Another study by Zaremba (2017) tested the semi-strong form efficiency of the LSE using a sample of FTSE 100 stocks from 1999 to 2016. The author found evidence that the LSE is semi-strong form efficient, which implies that prices reflect all publicly available information. Zaremba also found that the efficiency of the LSE has improved over time. However, there are also studies that suggest that the LSE may not be perfectly efficient. For example, a study by Kanas (2007) examined the performance of technical trading rules on the LSE and found evidence of some short-term inefficiencies.

Additionally, a study by de Bondt and Thaler (1985) found evidence of long-term overreaction and underreaction in the LSE, which suggests that prices may not fully reflect all available information. In terms of financial data, the performance of the LSE has been mixed over the years. For example, in 2020, the LSE experienced a sharp decline in the first quarter due to the COVID-19 pandemic, but the market recovered strongly in the second quarter and ended the year on a positive note. However, there have been periods where the LSE has experienced prolonged bear markets, such as the one that occurred during the global financial crisis of 2008.

review carefully key academic literature and relevant published empirical evidence on EMH relating to the selected stock exchange market, and (2) carry out your own financial data analysis based on a graphical analysis of the movements in a relevant daily share/stock price index , over say a 90- days period, to arrive at a conclusion.