"SPDR S&P 400 US Mid Cap UCITS ETF" is an exchange-traded investment fund (ETF). It refers to the S&P Mid Cap 400 Index. This index reflects the development of 400 US American stocks and is therefore relatively well diversified. The ETF replicates its index using full physical replication, so it contains all the securities of its reference index. The ETF's earnings (dividends) are automatically reinvested (accumulated). The fund company SPDR claims a total expense ratio (TER) of 0.30% per year. The yearly average divergence from the index performance (Tracking Difference) since 2013 was 0.13% per year. Therefore, the ETF was less expensive than the TER suggests.
Comparing Tracking Difference, Total Expense Ratio and fund size
Every bubble represents an ETF. The further to the right it is, the higher (worse) is its tracking difference. The further up it is, the higher the total expense ratio specified by the fund company. The bubble's area represents the fund volume.