http://api.bitcoincharts.com/v1/csv/

gistfile1.txt

using System;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Net;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace DownloadZips
{
    class Program
    {
        public static readonly string url = "https://api.bitcoincharts.com/v1/csv/inactive_exchanges/";
        public static readonly string url_main = "https://api.bitcoincharts.com/v1/csv/";

        public static string HrefRegex() => @"<a href\s*=\s*(?:[""'](?<1>[^""']*)[""']|(?<1>\S+))>(?<name>\S+\.\S+\.\S+)</a>";
        public static async Task Main(string[] args)
        {
            await DownloadZipAsync(url_main, "BTC-History-2");
            RenameFiles(new DriveInfo("D"), "BTC-History-2", ".gz", "");

            Console.ReadLine();
        }

        private static async Task DownloadZipAsync(string url, string folder)
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
            using HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            using StreamReader reader = new StreamReader(response.GetResponseStream());

            Regex regex = new Regex(HrefRegex(), RegexOptions.Multiline);
            MatchCollection matches = regex.Matches(reader.ReadToEnd());

            if (matches.Count > 0)
            {
                foreach (Match match in matches)
                {
                    if (match.Success)
                    {
                        string nameDirty = match.Groups["name"].Value;
                        string req = url + nameDirty;
                        Console.WriteLine("Started: " + req);
                        DriveInfo drive = new DriveInfo("D");
                        await DownloadUnzipAsync(req, string.Format("{0}{1}{2}{3}{4}", drive.RootDirectory, '\\', "BTC-History", '\\', nameDirty[0..^3]));
                        Console.WriteLine("Finished downloading " + url);
                    }
                }
            }
            else
                Console.WriteLine("No match!");
            Console.WriteLine("Finished downloading all URLs.");
        }

        private static void RenameFiles(DriveInfo drive, string folder, string endswith, string replace)
        {
            Console.WriteLine($"Started renaming files in \"{string.Format("{0}{1}{2}", drive.RootDirectory, '\\', folder)}\" that ends with \"{endswith}\", replace: \"{replace}\"");
            new DirectoryInfo(string.Format("{0}{1}{2}", drive.RootDirectory, '\\', folder))
                .GetFiles()
                .Where(f => f.Name.EndsWith(endswith))
                .ToList()
                .ForEach(f => { File.Move(f.FullName, f.FullName.Replace(endswith, replace)); });
            Console.WriteLine($"Finished renaming files in folder: {folder}");
        }

        private static async Task DownloadUnzipAsync(string url, string name)
        {
            using var client = new WebClient();
            client.Headers.Add("accept", "*/*");
            byte[] filedata = await client.DownloadDataTaskAsync(new Uri(url, UriKind.Absolute));

            using MemoryStream ms = new MemoryStream(filedata);
         
            using FileStream decompressedFileStream = File.Create(name, filedata.Length);
    
            using GZipStream decompressionStream = new GZipStream(ms, CompressionMode.Decompress);
            decompressionStream.CopyTo(decompressedFileStream);
        }
    }
}