However, you're looking at the volume on one specific exchange which actually deviates a lot from the overall volume on all the exchanges.
If you look at CoinMarketCap total volume across all exchanges, you will see that the volume in April surpassed ATH of Dec 17 and Jan 18.
Bitstamp does not reflect this, because it lost popularity since then, plus there are many more exchanges today, and that dilutes the volume on single exchange.
I was surprised to discover that and I almost FOMOed in when I saw it, because that puts us exactly on your 3rd volume candle of Jun 19.
Total volume across exchanges in Dec 17 : 60B / Apr 19 : 80B
you can see my other ideas . I think we can reach 1600-1800 $ In June