The 'catalyst' was a crossover of the 10-Week and 21-week EMA on the very long range 1-Week chart. It's only the 4th such crossover in 2 years and crossed at 0.015 which is why there is still a lot of strength in the rally at this level since the market was well oversold for 2-3 months towards the end f last year.

The crossover has happened at successively higher points on the 1-Week chart over the 2 year period.

(Note: This is just the coin-to-coin price ratio with Bitcoin which is the most pessimistic measure as it doesn't take into account relative supply increase. Relative market cap against bitcoin has even more gain).