Bookmarklet: BITCOIN @ The World Factbook

bookmark.js

(function() {
    var request = new XMLHttpRequest();
    request.open('GET', 'https://api.coinmarketcap.com/v1/ticker/bitcoin/', true);

    request.onload = function() {
        if (request.status >= 200 && request.status < 400) {
            var data = JSON.parse(request.responseText);
            var market_cap_usd = Number(data[0].market_cap_usd);

            if (!('elBTC' in window)) {
                document.querySelectorAll('#rankOrder tr').forEach(function(el) {
                    var v = Number(el.children[2].innerText.replace(/[\$,]/g, ''));
                    if (v < market_cap_usd) {
                        if (!('elBTC' in window)) {
                            elBTC = window.elBTC = el.cloneNode(true);
                            elBTC.children[1].innerText = 'BITCOIN';
                            elBTC.children[2].innerText = '$' + new Intl.NumberFormat().format(market_cap_usd);
                            elBTC.children[3].innerText = 'NOW';
                            el.parentNode.insertBefore(elBTC, el);
                        }
                        el.style.cssText = (el.style.cssText) ? '' : 'background: #EEEEEE';
                        el.children[0].innerText = Number(el.children[0].innerText) + 1;
                    }
                });
            }
        }
    };

    request.send();
})();

bookmark.min.js

javascript:(function(){var e=new XMLHttpRequest;e.open("GET","https://api.coinmarketcap.com/v1/ticker/bitcoin/",!0),e.onload=function(){if(e.status>=200&&e.status<400){var n=JSON.parse(e.responseText),r=Number(n[0].market_cap_usd);"elBTC"in window||document.querySelectorAll("#rankOrder tr").forEach(function(e){Number(e.children[2].innerText.replace(/[\$,]/g,""))<r&&("elBTC"in window||(elBTC=window.elBTC=e.cloneNode(!0),elBTC.children[1].innerText="BITCOIN",elBTC.children[2].innerText="$"+(new Intl.NumberFormat).format(r),elBTC.children[3].innerText="NOW",e.parentNode.insertBefore(elBTC,e)),e.style.cssText=e.style.cssText?"":"background: #EEEEEE",e.children[0].innerText=Number(e.children[0].innerText)+1)})}},e.send()})()

Just create a bookmark with this content as URL.