agid])) { foreach ($g_flag_thread[$flagid] as &$val) { flag_thread_filter($val); } flag_thread_set($flagid, $g_flag_thread[$flagid]); } } return $g_flag_thread[$flagid]; } // 设置缓存 $key = flagid / $val = flagid下tid数组 function flag_thread_set($key, $val) { global $g_flag_thread; FALSE === $g_flag_thread and $g_flag_thread = website_get('flag_thread'); empty($g_flag_thread) and $g_flag_thread = array(); $g_flag_thread[$key] = $val; return website_set('flag_thread', $g_flag_thread); } // 删除flag下tid缓存 function flag_thread_delete_cache($flagid) { global $g_flag_thread; FALSE === $g_flag_thread and $g_flag_thread = website_get('flag_thread'); empty($g_flag_thread) and $g_flag_thread = array(); if (isset($g_flag_thread[$flagid])) { unset($g_flag_thread[$flagid]); website_set('flag_thread', $g_flag_thread); } return TRUE; } // Delete by tid / 通过tid删除flag下的主题和对应flagid缓存 function flag_thread_delete_by_tid($tid) { global $g_flag_thread; FALSE === $g_flag_thread and $g_flag_thread = website_get('flag_thread'); if (empty($g_flag_thread)) { $g_flag_thread = array(); } else { $thread = well_thread_read_cache($tid); $arrlist = flag_thread_find($tid, 1, $thread['flags']); $flagarr = $ids = array(); foreach ($arrlist as $val) { $flagarr[] = $val['flagid']; $ids[] = $val['id']; if (isset($g_flag_thread[$val['flagid']])) unset($g_flag_thread[$val['flagid']]); } website_set('flag_thread', $g_flag_thread); // 主键更新 flag_update($flagarr, array('count-' => 1)); // 主键删除 flag_thread_delete($ids); } return TRUE; } // 主键删除 通过$flagid删除flag下的主题和对应flagid缓存 function flag_thread_delete_by_flagid($flagid) { global $g_flag_thread; FALSE === $g_flag_thread and $g_flag_thread = website_get('flag_thread'); $read = flag_read_cache($flagid); if (empty($read)) return TRUE; $arrlist = flag_thread_find_by_flagid($flagid, 1, $read['count']); if (empty($arrlist)) return TRUE; $flagarr = $ids = array(); $n = 0; foreach ($arrlist as $val) { ++$n; $flagarr[] = $val['flagid']; $ids[] = $val['id']; if (isset($g_flag_thread[$flagid])) unset($g_flag_thread[$flagid]); } website_set('flag_thread', $g_flag_thread); // 主键更新 flag_update($flagarr, array('count-' => $n)); // 主键删除 $r = flag_thread_delete($ids); return $r; } ?>组保留的标签 余下为需要删除的标签 unset($oldtag[$key]); } } } if (!empty($oldtag)) { $tagids = array(); foreach ($oldtag as $tagid => $tagname) { $tagids[] = $tagid; } well_oldtag_delete($tagids, $tid); } $r = well_tag_process($tid, $fid, $create_tag, $tagarr); return $r; } // 删除标签和绑定的主题 function well_oldtag_delete($tagids, $tid) { $pagesize = count($tagids); $arrlist = well_tag_find_by_tagids($tagids, 1, $pagesize); $delete_tagids = array(); // 删除 $tagids = array(); $n = 0; foreach ($arrlist as $val) { ++$n; if (1 == $val['count']) { // 只有一个主题 $delete_tagids[] = $val['tagid']; } else { $tagids[] = $val['tagid']; } } !empty($delete_tagids) and well_tag_delete($delete_tagids); $arlist = well_tag_thread_find_by_tid($tid, 1, $n); if ($arlist) { $ids = array(); foreach ($arlist as $val) $ids[] = $val['id']; well_tag_thread_delete($ids); } !empty($tagids) and well_tag_update($tagids, array('count-' => 1)); } // 标签数据处理 $arr=新提交的数组 $tagarr=保留的旧标签 function well_tag_process($tid, $fid, $new_tags = array(), $tagarr = array()) { if (empty($tid)) return ''; // 新标签处理入库 if ($new_tags) { $threadarr = array(); $tagids = array(); $i = 0; $size = 5; $n = count($tagarr); $n = $n > $size ? $size : $size - $n; foreach ($new_tags as $name) { ++$i; $name = trim($name); $name = stripslashes($name); $name = strip_tags($name); $name = str_replace(array(' ', '#', "@", "$", "%", "^", '&', '·', '<', '>', '；', '`', '~', '!', '￥', '……', ';', '?', '？', '-', '—', '_', '=', '+', '.', '{', '}', '|', ':', '：', '、', '/', '。', '[', ']', '【', '】', '‘', ' ', ' ', ' ', ' ', ' '), '', $name); $name = htmlspecialchars($name, ENT_QUOTES); if ($name && $i <= $n) { // 查询标签 $read = well_tag_read_name($name); if ($read) { // 存在 count+1 $tagids[] = $read['tagid']; } else { // 入库 $arr = array('name' => $name, 'count' => 1); $tagid = well_tag_create($arr); FALSE === $tagid and message(-1, lang('create_failed')); $read = array('tagid' => $tagid, 'name' => $name); } $tag_thread = array('tagid' => $read['tagid'], 'tid' => $tid); $threadarr[] = $tag_thread; $tagarr[$read['tagid']] = $read['name']; } } !empty($threadarr) and tag_thread_big_insert($threadarr); !empty($tagids) and well_tag_update($tagids, array('count+' => 1)); } $json = empty($tagarr) ? '' : xn_json_encode($tagarr); return $json; } ?>内容的栏目 * @param int $category 0列表 1频道 2单页 3外链 * @return array */ function category_list($forumlist, $model = 0, $display = 0, $category = 0) { if (empty($forumlist)) return NULL; static $cache = array(); $key = $model . '-' . $display . '-' . $category; if (isset($cache[$key])) return $cache[$key]; if ($display) { foreach ($forumlist as $k => $val) { if (1 == $val['display'] && 1 == $val['type'] && $val['category'] == $category) { $cache[$key][$k] = $val; } } } else { foreach ($forumlist as $k => $val) { if (1 == $val['type'] && $val['category'] == $category) { $cache[$key][$k] = $val; } } } return empty($cache[$key]) ? NULL : $cache[$key]; } /** * @param $forumlist 所有版块列表 不分模型 * @param int $display 0全部CMS栏目 1在首页和频道显示内容的栏目 * @param int $category 0列表 1频道 2单页 3外链 * @return array */ function category_list_show($forumlist, $display = 0, $category = 0) { if (empty($forumlist)) return NULL; static $cache = array(); $key = $display . '-' . $category; if (isset($cache[$key])) return $cache[$key]; if ($display) { foreach ($forumlist as $k => $val) { if (1 == $val['display'] && 1 == $val['type'] && $val['category'] == $category) { $cache[$key][$k] = $val; } } } else { foreach ($forumlist as $k => $val) { if (1 == $val['type'] && $val['category'] == $category) { $cache[$key][$k] = $val; } } } return empty($cache[$key]) ? NULL : $cache[$key]; } /** * @param $forumlist 所有版块列表 * @return mixed BBS栏目数据(仅列表) 尚未开放bbs频道功能 */ function forum_list($forumlist) { if (empty($forumlist)) return array(); static $cache = array(); if (isset($cache['bbs_forum_list'])) return $cache['bbs_forum_list']; $cache['bbs_forum_list'] = array(); foreach ($forumlist as $_fid => $_forum) { if ($_forum['type']) continue; $cache['bbs_forum_list'][$_fid] = $_forum; } return $cache['bbs_forum_list']; } // 导航显示的版块 function nav_list($forumlist) { if (empty($forumlist)) return NULL; static $cache = array(); if (isset($cache['nav_list'])) return $cache['nav_list']; foreach ($forumlist as $fid => $forum) { if (0 == $forum['nav_display']) { unset($forumlist[$fid]); } } return $cache['nav_list'] = $forumlist; } ?>科技股如何选ETF
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科技股如何选ETF

2025-06-10 15:53:55   0次

科技股如何选ETF

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选择科技类ETF时，建议优先关注科创板ETF和人工智能主题ETF。具体可考虑科创综指增强ETF（如泰康上证科创板综合指数增强）和人工智能ETF（如AI算力ETF、信创ETF）。这类产品既涵盖硬科技核心资产，又能捕捉政策红利下的行业增长机会。从配置策略看，可将60%-70%仓位配置于宽基类科技ETF（如科创综指），剩余20%-30%布局细分赛道（如半导体、机器人ETF）。操作上宜采用逢低分批建仓、动态平衡的策略，避免追高单一热点。

这一选择的底层逻辑基于三重维度：首先是政策导向，2025年国务院将数字经济列为重点发展领域，科创板和人工智能相关企业获得税收优惠、研发补贴等全方位支持，政策红利持续释放。从数据看，科创综指自2024年9月行情启动以来累计涨幅达53.7%，远超上证指数22.5%的涨幅，印证了科技板块的爆发力。其次是产业趋势，全球AI算力投资年增速超30%，我国半导体国产化率从2020年15%提升至2025年35%，产业链自主可控进程加速。以恒生生物科技ETF为例，其跟踪指数成分股2024年净利润同比增长102.4%，显示科技领域已进入业绩兑现期。最后是估值优势，当前科创板块PE约28倍，低于近三年均值35倍，且机构持仓比例仍低于消费板块10个百分点，存在明显配置洼地。从资金流向看，2025年上半年科技类ETF净流入超143亿元，其中半导体ETF规模突破千亿，成为资金共识度最高的赛道。需注意的是，科技股波动较大，建议通过ETF分散风险，同时关注产品规模（优选超5亿品种）、费率（管理费低于0.5%）和跟踪误差（年化误差小于4%）等核心指标。

本题链接：

科技ETF科创板人工智能