With dozens of new exchange-traded funds (ETFs) coming to market every month, the industry has begun 2019 with momentum to keep growing. While the field is dominated by a handful of major issuers, including iShares, Vanguard and Schwab, comparably smaller players are constantly vying for investor attention as well. New ETF launches are one way to jostle for position. Nonetheless, launching an ETF tends to be different from, say, an IPO or similar type of event. ETFs typically must prove themselves and the viability of their strategies in order to gain investor support and assets, unless they come from an issuer that already has a strong and devoted client base.

Nonetheless, every so often an ETF launches with unusual momentum. In these cases, funds can grow their asset bases into the billions in a period of weeks or months. Below, we'll explore several of the biggest ETF launches of 2018.

1. Communication Services Select Sector SPDR Fund (XLC)

In September of 2018, the Global Industry Classification Standard confirmed changes to its sector categories. One of the major shifts was to the telecommunications sector, which absorbed some of the stocks which formerly occupied the consumer discretionary and information technologies sector in order to become the new communication services sector. XLC was designed to represent this new sector, and it received substantial attention by capitalizing on the category shift. XLC launched in mid-June of 2018 and drew net inflows of more than $3.4 billion by the end of the year.

2. JPMorgan BetaBuilders Japan ETF (BBJP)

The second-largest ETF launch of the year belongs to J.P. Morgan, an up-and-coming issuer in the ETF space. As a major player in the financial services world, J.P. Morgan was able to bring a massive client and asset base into its new, high-profile ETF launches in 2018. The BetaBuilders line of funds in particular benefited from the built-in customer list. Indeed, J.P. Morgan put its own clients' money into each of these funds, helping them to become some of the largest launches in the entire ETF industry.

The Japan-focused BBJP launched in mid-June of 2018 and ended the year with more than $3.2 billion in net inflows.

3. JPMorgan BetaBuilders Canada ETF (BBCA)

Like BBJP, J.P. Morgan's Canada-focused BetaBuilders fund also managed to draw significant assets in the span of under four months. BBCA launched after BBJP, in early August of 2018, and it accumulated more than $2.3 billion in net inflows before the end of the year.

4. JPMorgan BetaBuilders Europe ETF (BBEU)

A third J.P. Morgan BetaBuilders fund, this one focused on Europe, launched on the same day as BBJP. It saw net inflows of about $1.9 billion in the second half of 2018. While this is a significantly smaller figure than the inflows for BBJP, it nonetheless places BBEU in the number four spot among the biggest ETF launches of the year.

5. Barclays ETN+ FI Enhanced Global High Yield Exchange Traded Notes Series B (FIYY)

The lengthy name of one of Barclays' newest funds hints at the niche strategy contained within. The Enhanced Global High Yield ETN Series B (FIYY) is a highly bespoke product to be used by Fisher Investments for in-house strategies. In this sense, Barclays' fund is different from traditional exchange-traded products. It did not rely on an outside customer base which could be built up over time. Rather, it had a ready pool of assets waiting when it was launched in March. Overall, the fund brought inflows of more than $1.4 billion throughout the remainder of 2018.

6. JPMorgan BetaBuilders Developed Asia ex-Japan ETF (BBAX)

Rounding out J.P. Morgan's BetaBuilders set is the Developed Asia ex-Japan ETF (BBAX). Launched in August alongside BBCA, this ETF trailed its siblings. Still, with inflows of more than $800 million in a four-month span, BBAX was one of the most successful launches of the year.

7. Barclays ETN+ FI Enhanced Europe 50 Exchange Traded Notes Series C (FFEU)

Like FIYY, Barclays Enhanced Europe ETN was a specialized product for in-house use. Assets flowing into FFEU were about half of those going to FIYY. FFEU brought in about $766 million, although it was launched at the same time as FIYY.

Notably, both of these products launched during the same year in which Barclays closed 50 of its ETNs in order to significantly revamp its offerings in the exchange-traded product space.

8. SPDR Gold MiniShares Trust (GLDM)

Rounding out the list of the biggest ETF launches of 2018 is a miniature version of an already popular product. SPDR's Gold Trust (GLD) is one of the most popular ETFs overall, with assets approaching $30 billion. In late June of 2018, the SPDR Gold MiniShares Trust (GLDM) was launched to offer customers another means of accessing the gold market through the trusted SPDR system. Each share of GLDM represents 1/100 of an ounce of gold. This is effectively 1/10 of the representation of GLD; each share of GLD represents 1/10th of an ounce of gold.

By decimating the price of shares, SPDR was also able to lower the expense ratio of GLDM as well. At just 0.18%, GLDM has one of the very lowest expense ratios of any gold-focused ETF. By comparison, GLD's expense ratio is 0.40%. GLDM was also able to undercut its similarly-sized competitor, the iShares Gold Trust (IAU), which maintains a fee of 0.25%. All together, these compelling arguments for GLDM brought in more than $300 million in net inflows across 2018.