library(plotly) ; library(data.table) ;library(quantmod)
fromDate <- '2012-01-01'; toDate <- '2019-12-31' 
getSymbols(Symbols = c('HD', 'LOW'), src='yahoo', 
           from = fromDate, to = toDate)

df_stockPrices <- data.table(Date=index(HD), 
                             HD = as.numeric(HD$HD.Adjusted), 
                             LOW = as.numeric(LOW$LOW.Adjusted))

dfMelted_stockPrices <- melt(data = df_stockPrices, 
                             id.vars = c('Date'),
                             measure.vars = c('HD', 'LOW'),
                             variable.name = 'Stock',
                             value.name = 'Price') 

p <-  plot_ly(dfMelted_stockPrices, x = ~Date, 
              y = ~Price, color = ~Stock,
        type = "scatter", mode = "lines")