<?php
foreach ($stocks as $isin => $stock) {
    $platformKey = array_rand($stock['platforms']);
    $platform = $stock['platforms'][$platformKey];
    $uri = $platform['uri'];

    $documentSource = crawlDocument($uri);
    $document = openDocument($documentSource);
    $xpath = new DOMXPath($document);

    foreach ($platform['xpaths'] as $query) {
        $nodes = $xpath->query($query);

        if (!is_null($nodes[0])) {
            $amount = cleanNumber($nodes[0]->nodeValue);
            try {
                $stmt->execute([$isin, time(), $amount]);
            } catch (PDOException $e) {
                echo $e->getMessage();
            }
            break;
        }
    }
}