diff --git a/views/chart.php b/views/chart.php
index 09c05f8..89bb7a7 100644
--- a/views/chart.php
+++ b/views/chart.php
@@ -135,7 +135,7 @@ function renderChart(
     }
     CacheManager::set('poloniex-supported-currencies', $supportedCurrencies, 60 * 60 * 24 * 7); // asking once a week doesn't seem like too much
   }
-  if ($currencyB != 'btc' || !in_array($currencyA, $supportedCurrencies)) {
+  if (!in_array($currencyB, ['btc', 'usdt']) || !in_array($currencyA, $supportedCurrencies)) {
     return false;
   }
 
diff --git a/views/index.php b/views/index.php
index 6ff4323..b3ef275 100644
--- a/views/index.php
+++ b/views/index.php
@@ -72,19 +72,19 @@
     <section>
       <h2>Transparent SVG and PNG charts with your favorite cryptocurrencies</h2>
       <figure>
-        <img src="/charts/candlestick/dash-btc/7d/svg" alt="Poloniex Dash/BTC price">
-        <figcaption>7 day Dash price candlesticks in BTC <code><a href="/charts/candlestick/dash-btc/7d/svg">https://cryptohistory.org/charts/candlestick/dash-btc/7d/svg</a></code></figcaption>
+        <img src="/charts/candlestick/dash-usdt/7d/svg" alt="Poloniex Dash/BTC price">
+        <figcaption>7 day Dash price candlesticks in USDT (Tether USD) <code><a href="/charts/candlestick/dash-usdt/7d/svg">https://cryptohistory.org/charts/candlestick/dash-usdt/7d/svg</a></code></figcaption>
       </figure>
-      <p>Sparklines too! ETH 7 days: <img src="/charts/sparkline/eth-btc/7d/svg" alt="ETH 7d chart" style="vertical-align: bottom;">
-        <code>&lt;img src=&quot;https://cryptohistory.org/charts/sparkline/eth-btc/7d/svg&quot; alt=&quot;ETH 7d chart&quot; style=&quot;vertical-align: bottom;&quot;&gt;</code>
+      <p>Sparklines too! ETH/BTC 7 days: <img src="/charts/sparkline/eth-btc/7d/svg" alt="ETH 7d chart" style="vertical-align: bottom;">
+        <code>&lt;img src=&quot;https://cryptohistory.org/charts/sparkline/eth-btc/7d/svg&quot; alt=&quot;ETH/BTC 7d chart&quot; style=&quot;vertical-align: bottom;&quot;&gt;</code>
       </p>
     </section>
     <section>
       <h2>Build your own chart:</h2>
       <p>The URL is flexible:<br>
-        <code>https://cryptohistory.org/charts/{theme}/{currency}-btc/{timespan}/{format}</code></p>
+        <code>https://cryptohistory.org/charts/{theme}/{currency}-{btc|usdt}/{timespan}/{format}</code></p>
       <p>Theme: <code>dark</code>, <code>light</code>, or <code>sparkline</code>.</p>
-      <p>Currency: anything active on Poloniex. Prices are all in bitcoin.</p>
+      <p>Currency: anything active on Poloniex. Supports prices in Bitcoin or Tether USD.</p>
       <p>Timespan: <code>1y</code>, <code>30d</code>, <code>7d</code>, or <code>24h</code>.</p>
       <p>Format: <code>svg</code> (best) or <code>png</code>.</p>
       <p>If you use svg format, you can control some of the colors with GET parameters: <code>lineColor</code>, <code>markerColor</code>, <code>risingColor</code>, <code>fallingColor</code>. Some examples: <code><a href="/charts/dark/maid-btc/7d/svg?lineColor=5593D7&markerColor=29578A">https://cryptohistory.com/charts/dark/maid-btc/7d/svg?lineColor=5593D7&amp;markerColor=29578A</a></code> <code><a href="/charts/candlestick/fct-btc/7d/svg?risingColor=FE8534&fallingColor=00BAE9">https://cryptohistory.org/charts/candlestick/fct-btc/7d/svg?risingColor=FE8534&amp;fallingColor=00BAE9</a></code>