Вы можете использовать следующий код
library(reshape2)
library(highcharter)
df_m <- melt(df, id="date")
hchart(df_m, "line", hcaes(x = date, y = value, group = variable))
Вот данные
df = structure(list(bid = c(20.12, 20.09, 20.03, 19.86), ask = c(20.14,
20.12, 20.06, 19.89), date = structure(c(4L, 1L, 2L, 3L), .Label = c("03/11/2014",
"04/11/2014", "05/11/2014", "31/10/2014"), class = "factor")), class = "data.frame", row.names = c(NA,
-4L))