Is there a way to access securities in coarse universe?

I would like to do something like this :

public IEnumerable<Symbol> CoarseUniverse(IEnumerable<CoarseFundamental> coarse)
    {
        return coarse
            .Where(x => x.HasFundamentalData)
            .Where(x => x.Market == Market.USA)
            .Where(x => x.Price < 10m)
            .Where(x => Securities[x.Symbol].AskPrice > 0 && Securities[x.Symbol].Close > 0)
            .OrderByDescending(x => Securities[x.Symbol].AskPrice - Securities[x.Symbol].Close)
            .ThenByDescending(x => x.Volume)
            .Select(x => x.Symbol)
            .Take(10);
    }

Thanks