Masternodes are needed to verify new blocks in certain cryptocurrencies. However, unlike other nodes, they do not add new blocks to the network. To maintain a masternode, one needs to hold a certain amount of the protocol's cryptocurrency, and often a significant amount. In return for operating a masternode, the operator is rewarded in the native currency.
The Masternode portfolio on CGK has 39 coins included in the evaluation, of which the 5 coins with the best vol/cap are:
$VIC - ratio 30.65%
$PIVX - ratio 11.5%
$FLUX - ratio 9.74%
$ZEN - ratio 9.26%
$DASH - ratio 8.82%