How can I show Currency with Negative instead of Parentheis in ASP NET MVC?

It's all down to NumberFormatInfo.CurrencyNegativePattern. Presumably you've got the value 0, when it sounds like you want 1.

It's not clear whether you're currently using the user's CultureInfo, the server's one, or something else. But you could always clone whichever culture you're using, then modify the NumberFormatInfo.

Sample code:

using System;
using System.Globalization;

class Test
{
    static void Main()
    {
        var original = new CultureInfo("en-us");
        // Prints ($5.50)
        Console.WriteLine(string.Format(original, "{0:C}", -5.50m));

        var modified = (CultureInfo) original.Clone();
        modified.NumberFormat.CurrencyNegativePattern = 1;        
        // Prints -$5.50
        Console.WriteLine(string.Format(modified, "{0:C}", -5.50m));
    }
}