A new month is on the horizon, so what better time to make some new additions to your investment portfolio.

If exchange traded funds (ETFs) are of interest to you, then it could be worth taking a look at the four listed below.

They could be among the best funds out there and provide investors with exposure to groups of high quality stocks from across the globe. Here's what you need to know about them:

BetaShares NASDAQ 100 ETF (ASX: NDQ)

The first ASX ETF to look at is the BetaShares NASDAQ 100 ETF. It is arguably the best ASX ETF available to investors on the local share market.

This high-quality ETF allows investors to buy a slice of the 100 largest non-financial shares on the famous NASDAQ index. This is where you'll find all the big tech giants that offer products and services that we use every day. If the market is heading higher over the next decade and beyond, these companies are likely to be the ones leading the charge. Holdings include Nvidia Corp (NASDAQ: NVDA) and Tesla (NASDAQ: TSLA).

iShares S&P 500 ETF (ASX: IVV)

If you would like more diversified exposure to Wall Street then the iShares S&P 500 ETF could be the answer.

This fund gives investors access to 500 of the largest listed companies on Wall Street. This is a diverse group of high quality companies and household names such as Apple (NASDAQ: AAPL), Berkshire Hathaway (NYSE: BRK.B), Exxon Mobil (NYSE: XOM), Microsoft (NASDAQ: MSFT, Walmart (NYSE: WMT),and Walt Disney Co (NYSE: DIS).

Betashares Global Quality Leaders ETF (ASX: QLTY)

A third ASX ETF that could be a buy is the Betashares Global Quality Leaders ETF.

This popular fund has a focus on investing in the highest quality companies in the world and was recommended by Betashares.

There are in the region of 150 companies included in the fund that rank highly on four key metrics: return on equity, debt-to-capital, cash flow generation, and earnings stability. This currently includes Netflix (NASDAQ: NFLX) and Visa (NYSE: V).

Betashares Global Cash Flow Kings ETF (ASX: CFLO)

Finally, the Betashares Global Cash Flow Kings ETF could be an ASX ETF to buy.

This ETF focuses on global companies with strong free cash flow. Betashares recommended this ETF recently and highlighted that companies that generate high levels of free cash flow have a tendency to outperform the market over the medium to long term. This could make this fund a great long-term pick for investors.

Holdings currently include Alphabet (NASDAQ: GOOG) and Adobe Inc (NASDAQ: ADBE).