Market volatility might be causing some short-term pain, but for long-term investors, selloffs often open the door to opportunity.

With many high-quality ASX ETFs pulling back from recent highs, now could be an excellent time to build or top up a diversified portfolio.

If I were starting fresh with $5,000 to invest today, here's how I'd allocate it across three standout ASX ETFs.

Betashares Nasdaq 100 ETF (ASX: NDQ)

Allocation: $2,000

The hugely popular Betashares Nasdaq 100 ETF gives you exposure to 100 of the largest non-financial companies listed on the Nasdaq. This means investors get instant access to global tech giants like Apple (NASDAQ: AAPL), Microsoft (NASDAQ: MSFT), Nvidia (NASDAQ: NVDA), Amazon (NASDAQ: AMZN), and Meta Platforms (NASDAQ: META).

These are the companies powering the AI revolution, cloud computing, and digital advertising — and while their share prices have taken a hit recently, their business fundamentals remain incredibly strong.

Buying this ASX ETF after a pullback could prove smart over the long term. These businesses don't just survive downturns — they often come out stronger on the other side.

Betashares Global Cybersecurity ETF (ASX: HACK)

Allocation: $1,500

Cybersecurity is one of the fastest-growing sectors globally, and the Betashares Global Cybersecurity ETF offers direct exposure to a diversified basket of the world's leading cybersecurity firms.

This ASX ETF holds companies like Palo Alto Networks (NASDAQ: PANW), CrowdStrike (NASDAQ: CRWD), and Fortinet (NASDAQ: FTNT). These businesses are on the front lines of protecting everything from national infrastructure to your mobile banking app.

As cyber threats rise and governments ramp up spending, the long-term investment case for this sector only strengthens. Overall, the Betashares Global Cybersecurity ETF could be a smart way to tap into the digital defence theme, with companies that are critical to the future of the internet.

Betashares Asia Technology Tigers ETF (ASX: ASIA)

Allocation: $1,500

To round out the portfolio with some high-growth international flavour, I'd look at adding the Betashares Asia Technology Tigers ETF. This ASX ETF gives you access to the region's leading tech players, including Samsung Electronics, Tencent Holdings, Alibaba Group (NYSE: BABA), and TSMC (NYSE: TSM).

These companies are leaders in semiconductors, e-commerce, gaming, and hardware, with massive user bases and expanding global footprints.

Due to market volatility, valuations in this side of the market have compressed recently, but the long-term growth potential remains enormous across the region. As a result, now could be an opportune time to invest.