These charts show the total number of users for subreddits /Monero ang /CryptoCurrency as a percentage of the total users of /Bitcoin subreddit. Sudden spikes in total percentage indicate there's a new wave of people getting into other cryptocurrencies, not only in Bitcoin. When /CryptoCurrency dominance increase, it makes sense to expect that such projects will appreciate against the BTC pair. However, this is just and idea to observe.