Downloading S&P 500 Data to R

The cornerstone of your analysis and quantitative trading algorithms are data. There are lots of different ways how to do it in R (depending of what your investment instruments are). Today I am going to download data from finance.yahoo which are stock prices of companies included in S&P 500 index.

First of all, we have a list of S&P 500 companies saved in this csv file. I have removed one or two tickers.

1
2
3
4
5
6

library(quantmod)
library(tseries)
library(timeDate)
 
symbols <- read.csv("/home/robo/workspace/R-Test/sp500.csv", header = F, stringsAsFactors = F)
nrStocks = length(symbols[,1])

Then we have to specify the start date and make a loop to download all the data for every company in the list.

1
2
3
4
5
6
7
8

z <- zoo()
 
for (i in 1:nrStocks) {
 
	cat("Downloading ", i, " out of ", nrStocks , "\n")
	x <- get.hist.quote(instrument = symbols[i,], start = dateStart, quote = "AdjClose", retclass = "zoo", quiet = T)
	z <- merge(z, x)
}

I am loading quantlib, tseries and timeDate libraries for easier manipulation of data and because I am going to utilize them in the future posts.

I have encountered a strange problem several times when the provided URL couldn't be read. Have you had the same problem?