Get historical stock prices from Yahoo API for bulk lists of ticker symbols

getSymbols <- function(Symbols, src="yahoo", from="1990-01-01", to=Sys.Date(), 
                       verbose=TRUE, auto.assign=TRUE, ...){
  require(quantmod)
  
  if(missing(Symbols)){
    stop("Symbols argument must be supplied to getSymbols")
  }
  
  if(missing(from)){
    stop("from argument must be supplied to getSymbols")
  }
  
  if(missing(to)){
    stop("to argument must be supplied to getSymbols")
  }
  
  if(isTRUE(verbose)){
    cat("Getting data from", from, "to", to)
  }
  
  NewSymbols = Symbols
  
  for(i in 1:length(Symbols)){
    s = getSymbols(Symbols[i], src=src, from=from, to=to, verbose=FALSE, auto.assign=FALSE, ...