Creating a generic object from a list of xts objects using a nested loop

Hi, I'm new here and new to R.
I'm trying to create a generic object for all returns_i,j and all spotvol_i,j from a list of assets using a nested loop. The desired object should be defined in the bottom of the ''in-loop'' where I have put the comment in my code. I'd be grateful for any help.
I wrote the following code:

for (i in 1:length(assets)){
  uniquedates <- as.character(unique(as.Date(index(results[[assets[i]]]))))
  for (j in 1:length(uniquedates)){
    results[[assets[i]]][uniquedates[j]]
    # generic object for all returns_i,j, spotvol_i,j
  }
}

The desired object should ideally look like this:

Here is a link to my data if anyone should like to replicate:
Data

And here is the code you will need in that case:

library(xts)
library(highfrequency)

DK_feb2020 <- read.table("DK_feb2020.csv",header = TRUE, sep = ',', dec = '.',stringsAsFactors = FALSE)
assets=unique(DK_feb2020$INSTRUMENT_LONG_NAME)
pricelist <- list()
for (i in 1:length(assets)) {
  pricelist[[assets[i]]]<-DK_feb2020[DK_feb2020$INSTRUMENT_LONG_NAME==assets[i],]
}

for (i in 1:length(assets)) {
  dates <- as.POSIXct(
    sapply(1:nrow(pricelist[[assets[i]]]), function(x){
      paste(as.Date(pricelist[[assets[i]]][x,1]),pricelist[[assets[i]]][x,13],sep = ' ')
    }),format = '%Y-%m-%d %H:%M:%OS')
  pricelist[[assets[i]]]<-xts(x=pricelist[[assets[i]]]$PRICE_ORIG[order(dates)],order.by = dates)
  colnames(pricelist[[assets[i]]])<-'PRICE'
}
results <- list()
for (i in 1:length(assets)) {
  price<-aggregatePrice(
    pricelist[[assets[i]]],
    alignBy = "minutes",
    alignPeriod = 5,
    marketOpen = "09:00:00",
    marketClose = "17:00:00",
    fill = TRUE,
    tz = NULL )
  
  vol <- spotVol(
    pricelist[[assets[i]]],
    method = "kernel",
    alignBy = "minutes",
    alignPeriod = 5,
    marketOpen = "09:00:00",
    marketClose = "17:00:00",
    tz = NULL)$spot
  results[[assets[i]]]<-cbind(price,vol,'returns'=diff(log(price)))
  colnames(results[[assets[i]]])=c('price','spotvol','returns')
}

for (i in 1:length(assets)){
  uniquedates <- as.character(unique(as.Date(index(results[[assets[i]]]))))
  for (j in 1:length(uniquedates)){
    results[[assets[i]]][uniquedates[j]]
    # generic object for all returns_i,j, spotvol_i,j
  }
}

Many thanks.