title: quantmod omitting tickers in getSymbols
body: <p>I'm a complete beginner in R. I want to download historical data about current companies in S&amp;P500 using getSymbols for a few periods. Obviously, some of companies didn't exist in a given period and R stops downloading data for the next tickers. Is there any way to enable getSymbols to simply omit tickers if their data are not existing? It would be much easier to just get the S&amp;P 500 list for that period, but unfortunately it's not free.</p>